-—.
b-
.,1”
National Academy
“‘“
v
Of ..__ ‘Sciences 1-~ ~ ;:, , - National Ressarch Council .-1 I r g NUCLEAR SCIENCE SERIES .-. ,3 J :;.. k .-1 1: ,:1 : “i The Radiochemistry ;. .of the Rare Gases ,. s. -. ;r. ~ ., .--i . 1 .1 ..... , r r .,. i ..
Ii
i i’.-
COMMITTEE
ON NUCLEAR SCIENCE
L. F. CUR-, CkaJ~ National Bureau of ~anla
ROBLEY
D. EVANS, Vh
Mamaohuema
Ctinnas
Institute of Teohuology
J. A. IWUREN, Secrdury WeWl@mue Eleotrlc Corpratlon C. J. BO~ M RI* Nadooal
J.
W. IRVINE,JR.
Maeaachueetca
Laboratory
Nortlmeutem W. WAYNE Untverslv
SAMUEL EPSTEIN California Inetituw of Teohuology
Co~ratlon
of
NOW
York
D. M. VAN PA77ER Bartol Reaearoh Foudulon
LIAISON PAUL C. AEBER&XiO
J. HOWARD MO~EN National Solence Foudatlon
E. WRIGHT
WIIJJAM
OHlce of Naval Reoeamb
SUBCOMMITTEE WAYNE MEINKE, Chfnwux
ON RADIOCHEMISTRY HAHOLD NIBBY Mad Uhcmatory
of Mlchlgan
GREGORY R. CHOPFlorlda State Unlven9i~ GEORGE A. COWAN Loa Akuoa 6Ci~1fi0
MEMBERS CHARLES K. HEED U. S. Air Fome
AtOmio Energy Comnlionion
Unlverally
~~ of Mkhlgan
ROBERT L. PLATEMAN Iabmvltoire & Chhnie Phy81que
Amerioa
W.
UntveralW
J. J. NICKSON Memorial HoEJ@tal,
of Studada
HERBERT GO-ED? Nuolear Development
d Teohmlogy
E. D. IUEMA
ROBERT G. 00CHRAN Texan &@xhuml and Mechanical
U. FANO National Bureau
Illlanwa
GEORGE LEDDICO’ITE Oak RNational Labomtory JULIAN NIELSEN Hantbrd Laboratnrlen
Laboratory
ARTHUR W. FADLHALL ~nlvemi~ of Waahbgton
ELLIS P. STE~EHG &gonne National Laboratory
JEHOME HUDIS Brookhaven National Laboratory
PETER
EARL HYDE Unlverni@ of California
LEO YAFFE McGUl LInlvareilg
C. STEVENSON
University
(Berkeley)
of California
(L1vermore)
CONSULTANTS NATHAN BALL(XJ Cenma d’Etuda de l’Energle Mol-Da&
BalsIum
“
Nucleaire
JAMES DeVOE University of Michigau WILLIAM MARLow National Bureau of Smudards
d#6’J M733r. C,.1
The Radiochemistry of the Rare Gases
~
FLOYD F. MOMYER,
JR
Luwr6nc8 Radiaiia Labcwm WniveY8ity of Calijimtia Livermore, Calijbnch ,. . ... ., CMober
Iwo
PROPERTY
❑ ✎✿✎✎✎ ✎✎✎✎✎✎ ✎
subcommittee m Rndlochemistry of 8ciemces-Natiaid Research
Natimml Academy
PrMdin LIM. PAoo$0.75. b-ws,~~f=-u-m~*.D.c..
AW8MWhM
titidlbohiod
Calncil
FOREWORD
The Subcommittee on Radlochemlstry Is one of a number of subcommittees working under the Committee on Nuclear Science within the National Academy of Sciences - National Research council. Its members represent government, Wdustrial, ahd university laboratories in the areas of nuclear chemistry end analytical chemistry
The Subcommittee has concerned itself with those areas of nuclear science which involve the chemist, suchas the collection. and distribution of radiochemical procedures, the establishment of specifications for radiochemically pure reagents, availability of cyclotron time for service irradiations, the place of radiochemis.try in the undergraduate college program, etc.
This series of monographs has grown “out of the need for up-to-date comptlationa of radiochemical information and procedures. The Subcommittee has endeavored to present a series which will be of maximum use to the working scientist and F@ch monowhich contains the latest available information. graph collects in one volume”the pertinent information required for-radiochemical work with en individual element or a group of closely related ,elements,
An expert h the radiochemistry has written the monograph, following by the Subcommittee. The Atomic’~ergy the printing of the series.
of the partictiar a standard format Commission has
The Subcommittee is confident these publications useful not only to the radiochemist but also to the worker in other fields such as physics, biochemistry who wishes to use radlochemical techniques to solve problem.
W. Wayne Meinke, Subcommittee on
iii
element developed sponsored
will be research or medicine a specific
Chairman Radlochemlstry
INTRODUCTION This pared
Science
monographs The gas
cussion
on the early
sections
formation,
author
on the radiochemistry The Mr.
R.
A.
author
takes
for
for
appreciate
of the rare
gases
gases
was
pre -
of the Committee
as one of a series
and to some
.
of rare
rare
to general
devoted
The
last
gases
radioactive
of
three
from
rare
reviews
general chapters
targets,
gases,
of
disare
a dis-
and a collec-
gases.
receiving
or unpublished,
this
are
rare
counting
procedures
would
published
for
rare
the elementE.
monograph
of the removal
used
Council
to the radiochemimt
techniques
a discussion
of radiochemical
of all
of this
of interemt
of the
on Radiochemistry
Research
radiochemistry
of techniques
The
the radiochemistry
of the Subcommittee
of separation
cussion
with
of the National
propertied
respectively
tion
dealing
at the request
on Nuclear
rare
report
which
from should
readers.
any additional
be included
in such
ina report
gases.
opportunity
daRo za in the preparation
to acknowledge of this
iv
monograph.
the a,ble assistance
of
CONTENTS Foreword
.
Introduction
.
I. II.
General Table
.
.
.
.
References of Isotopes
III.
Review
of Features
Sample
Solution
V.
Counting Collection
Rare
. Pertinent
of He,
IV.
VI.
.
Ne,
1 – Removal
Kr Procedure
Removal
Procedure
6 – Separation
Procedure
7 – Removal
from
U03
from
.
8 – Determination
Wire
v
2
Etry
.
5
.
.
27
.
.
29 34
34
.
40
43
,
.
.
.
.
46
Xe
Product . 6 H20 Fission
Cathode
46
Xe Targets Gases
48 48
and its
of a Discharge .
of Active
by the Charged
.
.
Th Targets
.
1
.
Product
,
U02(N03)2
.
iv
.
and
.
.
of Long-lived
on the
.
and
Product
of Rn from
111 “’-
Gases
.
Purification 85 .
of Fission
or
Air
.
of Kr and Xe 235 Targets U
.
.
. the Rare
of Fission
Removal
Collection Tube
.
of Kr
of Fission
5 – Rapid
.
for
from
UMetal
.
Radiochemi
Separation
U Foil
Procedure
.
Gas
and Separation
UBee
4 – Recovery
. .
.
and Rn
and Xe
Products
from
.
Radiochemietry
.
Extraction,
from
Procedure
.
Subsequent
3 – Rapid
Xe,
in Rare
1 A – Removal
2 – The
Gas
.
with Carriers
of Kr
Industrial Procedure
Kr,
.
Procedures
Fission Procedure
.
Activities
Their Procedure
.
A,
of Interest
of Radiochemical
Procedure
.
to Rare
and Exchange Gas
.
Gas
.
.
49
.
51
Half-lives
Technique
(II)
The Radiochemistry
of the Rare Gases
FLOYD F. MOMYER, JR Lawrence Radiation Laboratory University
of CaUforrda
Livermore, I.
GENERAL
REFERENCES
H.
Treatise
Remy,
Anderson),
R.
T.
R.
and Sons
E.
Dodd
Chap. S.
Vacuum
2,
Elsevier
Brunauer,
I.
New
Keulemans,
York,
1959, A. .-
Charcoal
A.
Book C.
D.
Fission ~ooka 64-70,
and R.
K,
Products,
139,
of Gases
York
Compounds,
1949.
John
Chemistry
(1954).
and Vapors,
Press,
Ad~orption
Vql.
Princeton,
.1,
N, J.
Reinhold
ling,
Energy
York,
Laboratory
editors, Series,
I’Physical (1942),
Publishing
Co.
,
and Xenon report
on Activated
1092,
MLM-
McGraw-Hill 145-50,
Vacuum Div.
I,
Equipment Vol.
1,
and Tech-
McGraw-Hill
1949.
Sugarman,
National
141,
of Krypton
II Mound
Waker
Nuclear
and N,
2 and 3,
York,
1959.
, blC, , New
Coryell
New
Inor~anic
Chromatography,
llThe
Weller,
National Co.
S.
2nd edition.
Ohio,
Guthrie
niques,
Gas
and Sons,
of Volatile
, New
University
A Bibliography,
Miamisburg,
Wiley
by J.
(1956).
Experimental
Co.
Adsorption
RDIOCHEMISTRY
( 1948).
Robinson,
Princeton
M.
Lawrence
York
Publishing
The
Adsorption”, A.
L.
John
GAS
VO1. I (translated
, New York
Manipulation
, New
and P.
Co,
Technique,
Vacuum Inc.
TO RARE
Chemistry,
Publishing
Sanderson,
Wiley
PERTINENT
on Lnorganic
Elsevier
S. Dushman,
California
editors,
Nuclear Book 154,
Energy Co.
, Inc.
and 311-17.
1
Radiochemical Series, , New
Div. York,
Studies:
The
IV,
9,
Vol.
1951.
Papers
II.
TABLE
OF
ISOTOPES
KRYPTON,
Isotope
Half -life
He3
Stable
OF
XENON
Type
HELIUM, AND
NEON,
RADON
of Decay
(abundance
1.3
(abundance
1. 7X10-5%
X10-4
(abundance
-looyo)
ARGON
,*
Method
~Oatmos.
)
of Preparation
Natural
wells) Natural
He4
Stable
He6
-0.8
P-
Be9(n,
Ne18
1.6sec
P+
F 19(PF 2n)
Ne’9
-18
P+
F19(p,
sec
sec
a)
n)
Ne20
Stable
(abundance
90. 92%)
Natural
Ne21
Stable
(abundance
0.257
Natural
Ne22
Stable
(abundance
8. 827’)
Ne23
-40
Ne24 A35 A36 A37
A38 A39 A40 A41
A42
sec
min
-1.8
sec
Stable
(abundance
-265 Stable -110
(abundance
Kr76
9.7
Kr77
-1.2hr
Kr78
Stable
Kr79
34,5hr
Mg26(n,
a)
*’
Listed Isotopes”, Phys. 30, the ori~nal
n);
C137(d,
2n);
Ca40(n,
a)
a);
A38(n#y);
K39(nFp)
N“atural
P-
A40(d,
P); A40(n,
K41(n,
p)
P-
A41(n)~); Y89(p, ~+ -80910
parent
Y);
K
42
span)
Se74(a,
n)
Natural
o. 3547,) EC
(abundant
n)
n); K39(d,
957”,
~+57°
Se76(a,
n);
Br79(d,
2n);
(p, n);
Kr78(d,
p);
Kr78(n, Stable
C135(p,
C137(p,
Br79
Kr80
p) n);
Natural
EC-20~0, (abundance
p);
S34(a,
EC
hr
Na23(n,
Natural
99. 6007’0)
~3.5yr
p);
P+
P-
min
Ne22(d,
S32(a,
O. 063%)
yr
y);
Ne22(t,
EC
(abundance
Ne22(n,
P-
0.337%)
day
Stable
Natural P-
3.38
-35
~,)
y)
Natural
e 2. 27~0)
are those nuclides having an IIAII or IIBII classification and G. T. Seaborg: D. Strominger, J. M, Hollander No. 2, Part II, April 1958. Further information and literature may be found in said article,
2
in llTable
of
Revs. Mod. references to
TABLE
Isotope
OF
ISOTOPES
-10
Kr’1
2.1X105
Kr82 Kr83m
Stable
He,
Ne,
.sec yr (abundance
A,
Kr,
Xe,
and Rn,
of Preparation
IT
Brsl(p,
n);
daughter
EC
Kr80(n,y)
Se80(a,
n);
Kr82(d,
p);
Kr82(n,
y);
x-rays
on
of Decay
IT
. Kr83; Br83; Kr83
Stable
Kr84 Kr85m
Stable 4.36
11, 557.)
(abundance
56. 90!70)
U, daughter
~aughte
r Rb83
Natural;
~-78~0,
IT 22~0
Se82(a, Kr84
10.3
yr
Stable
Kr84(n,
P-
(abundance
P-
78 min
fission
U
Kr84(d, Rb85(n,
y);
fission
y);
Kr86(d,
p);
Rb87(n,
p);
fission
U
U,
Th
Kr89
3 min
P-
Fission
U,
Pu
Kr90
33
f3-
Fission
U,
Pu
Fission
U,
Pu
Fission
U,
Pu,
Fission
U,
Pu
Fission
U
Kr94
l,4sec
Kr97 xe121
1 sec
PF F PP-
40 min
P+
20 hr
EC
2 hr
EC,
9.8
Kr92
3. Osec
Kr93
2.0
xe122 xe123 xe124 xe125m
xe125 xe126 xe127
sec
sec
Stable
(abundance
IT
hr
Stable 75 sec
(abundance
1127
(?)
Th
PU
(p, 5n)
Natural 1127 (a,6n)Cs
O. 096~,)
55 aec
18.0
Fission U, 1127 (p, 7n) 1127 (p, 6n) f3+
U U
Kr86(n,
Fission
Kr9’
U,
fission
i=
aec
p);
fission 85 Br
2.8hr
Kr88
p);
a);
Natural;
17. 377.)
U
n);
daughter Kr85
fission
(n, y);
Sr88(n,
Kr86 87 ,Kr
81
fission
Natural;
(abundance
hr
Rb
Natural
11. 56~0)
114 min
(Cent’d]
Method
Type
‘Half - life
Kr81
OF
125;
daugh-
EC
ter Cs125 Te122 (a, n) Xe 124(n,
IT
Natural 1127 (a,4n)Cs
o. 0907,)
ter (Table
3
127;
y)
daugh-
Cslz7
Continues
on page
4)
TABLE
Isotope
~e127
OF
ISOTOPES
OF
Type
Half - life
36.41
He,
Ne,
A,
Kr,
and Rn.
Stable
xe129m xe129 xe130 xe131m X=131 ~e132 xe133m xe133
8.0
(abundance
(a, n);
IT
Stable
(abundance
26. 447.)
Natural
Stable
(abundance
4. 08~0)
Natural xe131
12.0
day
IT
(abundance
21.
Stable
(abundance
26. 89~~)
-2.2
18%)
day
5.270
(n, n’);
13-
fission xe134
Stable
xe135m
-15
(abundance
IT
fission
9.13
xe134
hr
P~e136
(n, a);
fission
(n, y);
Xe134(d,
Stable
xe137
3.9min
xe138 ~e139 Xe 140 xe141
Rn206 Rn207 Rn208 Rn209
Rn21 2 ~n215
(n, y);
PP-
Fission
U,
Th
-10
P-
Fission
U,
Th
P-
Fission
U
P-
Fission
U
Fission *U197
U
sec sec
-1
sec
f3-
-6
min
a65~0,
EC 35~0
-10
min
EC 96~0,
-22
min
EC-80~0, EC 83~0, a-96~0,
hr
EC
16 hr
a
23 min -10-6sec
(est.
)
a
74~0,
a470 a-20~o a 17~0 EC-4~o a26%
U
(N14, *U197(N14 Span
p);
Th;
Spall
Th;
Span
Th;
Span
Th;
U
fission
17 min
2.7 1
fission
41 sec
30 min
~n210 ~n21
P-
l. Osec
Xe 144
Natural; ~e136
8. 8770)
U
U
Fission
-2
~e143 8
(abundance
y);
Ba 138(n,
(n, 2n);
fission xe136
U
Xe 134(n,
(n, 2n);
Ba138 ~e135
U
U
U
Natural; xe136
10. 4470)
min
fission
fission
Natural; fission U xe132 (n, y); fission U xe132 (n, y); Xe 132(d, p); ~e134 (n,2n); Te130(a, n); ca133 (n, p); Be 136(n, a);
IT
day
(njy)
Natural;
Stable
1127( d,2n)
Xe Iz+n,y)
(p, n);
Natural xe128
1, 919L70)
day
of Preparation
~e124 1127
xe128
(Cent’d)
Method
of Decay
EC
day
Xe,
U
5n) , 4n)
span) Pb(C12, .Pb(C 1’, span) 12 Pb(C , span) .. span) Pb(C l’,
SpaU Th; Pb(C12, SP1l) 232 U-2 27 chain from Th (a, %)
a);
TABLE
16
OF
0.019
Ne,
(est.
A,
Kr,
Xe,
and Rn,
)
~228
from
Th
a
(a, 8n) ~229 chain
from
Th
a
(a, 7n) ~230 chain
from
Th
a
Member
(a, 9
Rn2
3.92
sec
of Preparation
chain
a
sec
(Cent’d)
Method
of Decay
sec
10-3
8
He,
Type
-10-4sec
Rnz17
Rn2
ISOTOPES
Half-life
Isotope
~nz
OF
232
232
232
6n) ~235
decay
chain Rnzzo
51.5sec
~nzz
1
25 min
Rnzzz
~- -80~’,
3.8229
day
Th232
Member
a
chain Thz32
a-20~o
(p, span)
Member
a
decay
U238
decay
chain
III.
REVIEW
OF
IN RARE
The krypton,
rare xenon,
of half-life One
can
gases
from
each with
from
the procedure Reviews in most
texts
chemically
chosen
literature
and
of the
other
to quantitatively
As
rare
greatly
helium gases
will
the further
often
be
simple
of the rare gases propertiesil 1 chemistry. In a practical sense,
They
will
remove
remain impurities
5
chemically other
unaltered than
rare
will
like-
generally
and in a regular
to radon,
concerned
monograph
separations
re-
and from
is ‘largely
gas
rare
However,
and xenon
products
‘Ichemical
on inorganic inert.
xenon.
rare
fission
sense.
four
be necessary.
in this
argon,
isotopes
remaining
of krypton
radiochemistry
discussion
varies
from
might
other
neon,
in the ordinary
of the
separation
gas
helium,
no radioactive
studies
separation
from
are
possess
one another
detailed
which
the group
the
is the
on rare
krypton
to include
and neon
elements
and most
property
through
by far
INTEREST
table,
radio chemical
and from
of heavy
around
on some
proceeds
are
The
problem,
center
depend
O of the periodic
in which
problem
OF
RADIOCHEMLSTRY
Helium
situations
fission
GAS
to permit
contaminants
other.
wise
enough
common
this
Group
and radon;
long conceive
the most sulting
gases,
FEATURES
manner
as
application
one of
if required. will
be found
the rare
gases
in any
reactions
gases
from
them.
rare
However, their
gas
atoms
neighborhood.
chemical
established.
the rare
Waal!sr’
for
solubilities
gas. ” A number
plicable
over” wide
ranges
comprehensive
studies
and xenon
gas
from
of organic
liquid
‘remember
moval ical for
rare
that
condensation of rare
gases
from
Thus
essentially
generally
liquids
the
gas
reasons
of the group
solids
Rare
gas
atoms of these
crystal
(one
rare
One
system may
solution,
corresponds
added
with
parti
tion
differences
to
or in reor phys -
usually
species
added
to be
recently
The
which
per
in some
loss
from physical
than
by
pressure.
crystal,
of rare
the gas
The
in the
actual
on the conditions
the theoretical been
described
to 25%
in the
of
limit.
prepared
for
use
reference
of the theoretical
as
re This
limit.
in the gas phase at about 25 atmospheres 85. per gram of clathrate (using fission The
of activity
material
and the 10Ss
day if the material
dissolve
operations
gases
preparation equal
prepared
ulting
markedly
krypton
have
considerable
molecules).
less
5~0 Kr 85).
on elements
of the rare
well
walls)
at high
on the amount quinol
depends
is about
no appreciable
chemical
crystal
of Kr
per .m”illion.
performed
stream
result
are
for
gas
the re;
considerably
in 3 curies
which
substances The
are
in the
to the concentration
powder
limit
ever y three
concentrations
and results krypton
other
gae
rare
within
an upper
for
and is usually
product
krypton
adsorption
carriers
are
of the
in “cages”
setting atom
of rare
in krypton
pressure
few
gas
of fission-product 85 5 activity. of Kr
sources
of the more
recovering
or solids
gas
carriers
an atmosphere
contained
cages
rare
crystallization
suits
under
are
number
Clathrates
on sol-
law is ap-
one does
(including
of
solutions.
quinol
concentration
known
number
(Henr yls
for
been
relatively
atomic
A series of substances known as clathrates has received 3,4 study, Clathrates of argon, krypton and xenon have been crystallizing
are
are
dependence
gas
amounts,
through
work
has
in a counter-current
liquids
phase
that
with
system
tracer
of other
+
and He2
in the literature.
absorption
or
+
volubility
a proposed
in
considered
of solvents
‘of the rare
appeared
phase
gas
or ions
here.
as HeH
increase~
of rare
in quantitative
‘the same
from
members
especially
with
the gas
properly
in a number
by their 2
gases,
contact
from
occlusion.
separated
streams
(kerosene).
in handling
heavier
gases
outlines
molecules,
is of no concern
pressure
) have
also
are
such
of studies
and partial
temperature,
atoms,.
of species
the four
solvent
other
inter actionfi
in nature
of rare
in a given
with
these
in discharges
Hydrates and
Volubility
vent,
der
existence
to exist, high.
Whether
or ‘Ivan
The
do interact
may
be ground
on standing
is protected
from
is
water
to a only
a
and
quinol.
involved
in separating
or compounds
other
one another
must
property
(usually
6
than
and purifying rare
gases.
be accomplished vapor
pressure
rare
gases
The
separa
on the basis or extent
of
of
-
It may
adsorption).
often
happen
that this
physical
rate
some
or all
of the impurities
other
rare
gas.
Thus
it is
necessary
the
rare
ical
gases
be possible
exist
as
Depending
Substances may
which
may
At said
being
to denote
critical
here
temperature
unsaturated
atmosphere
but which
that their rated
partial
vapors
fined
pressures
The
in the
word
context
often
be purified
in target
dissolution
must
of nitrogen, amounts
and occasionally
of elemental
of these. been
The
list
or could
small Methods
is by no means
be used,
pressures;
but it is hoped
must
as
that
and
3)
of air,
listed
and trace below
methods
it is representative
species
and otides
of hydrocarbons are
category, rare
volatile
halides
regards
be de-
The
from
satu-
vapor
is a large
small.
one
enough
of course
hydrogen
of removal
complete
than
appreciable
the above
amounts
less
but small
having
constituents
their
1 atmosphere;
are
is quite
as hydrogen,
from
halogens.
vapor
liquids
of
the term
above
than
which
temperature
1) gases,
appreciable
Although
the
such
to those
greater
encountered
from
limited at the
-
amounts
be necessary.
phase
in the foregoing
usually
in a radiochem
will
pressures
their
or
of the experiment.
gases
are
sepa -
to purify
and their
of substances
vapor
than
solids
‘Iappreciablelr
of contaminants
involved
less
steps
include:
in amounts
with
the number
will
pressures
whose
or
species
gases
also
a particular
convenient
step
amounts
vapor
are
in equilibrium
pressures.
this
appreciable
present
most
in the gas
will
from
whatever
rare
temperature
are
nor
operations
substances
gases
as the first
contaminate
or having
vapors,
separation
rare
contaminating
concentrations
the experiment.
2)
a group
upon the
that no chemical
in appreciable
used
neither
chemically
procedure.
it may
often
than
for
which enough
each
have to be
useful. 1)
Nitrogen:
with
titanium
(ea.
850°C)
Quartz the
Mole
sponge, has
14-20
been
or ceramic
softening
point
amounts mesh
reported.
6
furnaces
are
of Pyrex
glaes
so the temperature
must
prevent
of the furnace.
destruction
to remove passive this phase
nitrogen through
problem with
nitrogen 2) gen also 3)
may at
be quantitatively 1000 -11 OO”C.
Oxygen necessary es .
(400 -5.00 ”C).
reaction
and flow Calcium
Calcium
of surface
Use
films.
has
temperatures
been
however,
For
small
are
above
exothermic
of the gas
often
does,
temperatures
quantitatively.
is quite
rate
by reacting
of lower
removed
as these
The
be monitored
formation
is also
removed
and
controlled
used tend
amounts
to
satisfactorily
to become of impurities
is
sometimes circumvented by conducting the reaction in the gas 7 Ca vapor. Clean uranium turnings at 800 “C will also react with
(and decompose Oxygen: reacts
Will rapidly
Hydrogen,
hydrocarbons). be removed with
carbon
with
copper
nitrogen
turnings
monoxide,
light
7
in the above
above pa,raffin
350”C
reactions
to give
hydrocarbons:
.
Oxy-
CUO. Passage
of the gas
stream
rapidly.
over
CUO
Hydrocarbons
temperature moval
will
of 900”C
of oxygen
temperatures
oxidize
that
in like
to achieve
be necessary
used
will
be oxidized
is necessary
may
are
at 500”C
HZ to H20 manner
rapid
(and is easily
9
and CO
to H20
and C02
reaction.
pregsure
to condensation
of water
but a
Subsequent
accomplished),
the dissociation
to C02
re-
if high
of oxygen
over
enough
CUO becomes
appreciable.
often
4)
Water:
not
specific
of a number
In addition enough),
water
of desiccants
.
may
P205,
be removed
Mg(C104)2;
in cold
traps
by passage and CaC12
(a method
through
are
any one
representative,
with
equilibrium partial pressures of water over them at room temperature -5 and O. 2 mm Hg respectively. Ofzxlo , 5 x 10-4, P205 and CaC12 rep-
resent
the
chlorate poses
extremes
has
of efficiency
achieved
and is easily
Where
large
CaC12
to remove
maining 5)
by distilling are
involved,
of the water
dioxide:
Ascarite,
May
and then
impregnated
with
of NaOH
and CaO
solution
of alkali
metal
convenient
.
enough
Magnesium
for
per -
practically
all
pur-
the water
off in vacuo
at 220-C,
gases
often
first
with
are
dried
Mg(C104)2
Hydrogen
7)
Oxides
by passing
commercial
with
to remove
may
also
re -
systems
than
May
be removed
halides:
Sweeping
effective. solid
through
which
Sofnolite,
be used.
is also
the gas
preparation
hydrotide.
sodium
hydroxide
in vacuum
6)
be removed
a granular
mixture
leas
as it is efficient
of water
most
desiccants
of moisture.
Carbon
asbestos
use
regenerated
amounts
traces
containing
wide
in common
is
a trap
essentially
or soda-lime, the gas
Solutions
materials,
a
through
are
a
sometimes
“however.
in the same
manner
as carbon
diotide.
in evolution
2 small
in relatively reduction
with
solution
tion
are
oxides available
may
often
to be removed. zero
gas
through
change
oxidation
the gas
into
Free
a solution
to non-volatile of the halogens
most
will
be accomplished
are
all
relatively
amounts
in targets
solution
process
leaves
of sodium species their
will
hydroxide (halide
will
rapidly
and hypohalite
corresponding
8
them
halides
a
N02
may
hydroxportion
methods
of
of solu-
of nitric
acid,
and active which
partly
be contaminated.
and
a good
the use
from
occurs
with
of sodium
volatile,
in trace
stream
wash
result
by catalytic
NO
If alternate to avoid
will
usually
the gas
a solution in fact
flask.
convenient
acid N20
by scrubbing
through
reflux
the dissolver
the gas
with
may
.
as permanganate.
#tream
under
in nitric
proportions
to NO
such
halogens
If the state,
removal
agent
solution
back
of targets
in varying
2
Its
oxidizing
be present
are
NO
or by oxidation
it is often
the
halogens
Dissolution
and
amounts.
the
8)” Halogens: gens
NO
by sweeping
Performing
the higher
O,
hydrogen
of strong
be removed ide.
of nitrogen:
of N
rare
halogases
or entirely Sweeping
in the
convert all the free 10 The rapid ex). in solution
is another
useful
means
titatively used
of decontamination
removed
as a trap
by contact
packing
for
from with
this
tracer
silver
halogens
(silvered
purpose).
Iodine
11, 12
.
Raschig
Iodine
rings
is reduced
is
have
quan been
to iodide
in NaHS03
solution. Where pleted
dissolution useful, with
device
which
These
for
rates
consist
used
may
Alternate
be useful
rates
may
in particular
of a c’hamber
designed
and cooling
is the
to permit
pressure
hour.
and electromagnetically operated has 14 Pressure differentials developed minute,
per
the chamber 15
pressure
Another
achieves
by means
Other been only
rates
circulat-
designed. unidirectional within
the
of a few
not noted
similarly
of a mylar
target
generally 13 pump,
in the chamber has been 13 An iron piston enclosed
were.
small.
from most
changes
produced
probably
not be com-
Toepler
have
in glass
but are
off gases
be obtained.
of the gas per
may
and still
instances
periodic
of O. 5 liters
the
classic,
of gases
minute
of producing
heating
flow
The
(or transfer) per
that purification
to circulate
train.
a liter
essentially
to achieve
S1OW enough
be necessary
circulation
and a means
chamber.
are
a purification
of about
which
of gas
rates it may
through
ing pumps
flow
reaction
in one pass,
high
diaphragm
in the
flow
rates
driven
liters
reference by pulsing
by high
pressure
gas.
Ultimately properties
the radiochemist
of the rare 16
of interest.
gases.
must Table
concern
1 summarizes
Table
He abundance
Atmospheric (Volume
x 10
%)
1.82 -4
with
some
the physical
data
which
may
A~
Kr
0.934
1.14
-3
Xlo
Xe
w 6 x 10-18
8.7 -4
Xlo
Xlo
-6
Boiling
Point
( ‘C)
-269
-246
-186
-153
-107
-65
Melting
Point
( “C)
-272
-249
-189
-157
-112
-71
3.82
3.94
4.36
(25 Atomic
diameter
in
crystal
(angstroms)
Distillation for
separation
successfully
and radon
and adsorption of the
rare
of helium
which
is
techniques
gases.
The
commercially which
obtained
) 3.20
3.57
produced
the exceptions
atm.
be
1
Ne
5.25
himself
are
pure
rare
those gases
by the fractional
is extracted
as a member
9
from
which have
Texas
natural
come
of course
distillation
certain
of the 4n+2
first
----
to mind been
of air, natural
radioactive
with gases decay
series.
Fractional
distillation
istry
and the fractionation 17-20 places . Glueckauf air
to use
there
will
such
low
be used rough
air
texts
on physical
is discussed
combining
in practically
red
every Thus
till
prove
to the generally
necessary
for
pressure
chem -
in numerou8
fractional
distillation
of
for
which
Efficiencies
pressure
of its
ample,
solid
the vapor
99V0 of the Kr cold
veniently
available
amounts enough
The
of necessity
a system, absorbents
such
resort
as
gases
such
krypton
inter diffusion sure
orders
Kr,
of below
Xe,
curves
is often
losses,
for
is 2-3
Rn at low
seriously
lower
Thus
may
one wishes
in manipulations “he may wish to perform. -6 10-5 to 10 mm Hg are easily constructed
rates
IQ
to 2-3
and will
krypton
small
vapor
mm
of small
slowness system pressures
with base suffice
If one Hg from
refrigerated
of transfer
a vacuum
Systems
initial
be made
Presence
the lowest
at
and convenience.
due to the relative
than
con-
and the [argest
refrigerants,
the
an ex-
in an attached
increasing
they
pumps.
As
so roughly
the coldest
systems
comparable
temperature
or Toepler
lower
with
of speed
at pressures
trap.
by condensation
smallest
usually
conby the
to the vapor
be collected
manipulated
sake
species
determined
“mm Hg,
is generally
decrease
--
the
are
in the system
may
nitrogen
condensation,
processes.
vapor
temperature
in the cold
at -195°C
by using the
to lower
of magnitude
data
In order
of a gaseous
species
Hg pressure
Kr
krypton
may
for
tabulates
pres sure
system
condensation
practicable
charcoal,
is refer-
22
Physics ) also
as
commonly’
reader
A and 02,
vapor
to the
of the
liquid
acceptable
of noncondensible as the above
As
resultant
collect
he must
N2,
as the transfer
Kr
at 20 cm
carrier
the y are
and
et seq.
at a given
are
have
attached
after
be minimized
of krypton that
in pairs
of solid
refrigerant,
and may
pressure
pressure
at - 195°C.
species The
at low temperatures.
gases
such
trap
or liquid
in a system
trap
781
pressures
similar.
partial
pressure
temperature.
pressure
very
volatile
will
or effecting
) of vapor
Chemistry
(page
vapor
listed
to a cold
of the initial
of
of substances
of processes
in a system
small
are
and other
Handbook
the common
so
processes
gases
t~mperatures
to the radio chemist.
Dushman23
Gases
condensation
and
low
gases
(decreasing
and H20.
temperatures
rare
in the laboratory
in transferring
( for
handy
a number
temperature)
and C02,,
relation
for
a plot.
volatility
the critical
experiment
very
columns
here.
distillation
a plot
available
such
data
decreasing
tained
simple
of temperature
encountered
fractionation
of the method
hand,
separations.
a function
eous
a procedure
temperature
be no discussion
On the other
pres
in most
from
techniques in the determination of krypton and xenon con21 It is very ~likely that the radiochemist will have of the atmosphere.
need
must
used
gases
and ads orption
tents
this
is discussed
of rare
for
amounts
proces
sea
of gas with
a base
involved
pressures
of
the,” rnamipula-
tions
involved
than
tracer
in most
amounts
Removal when
of only
than its
tially
their
stream
lost
(passing
pres
sure
cold
through
prevent
are
isfactory.
materials
Such
the induction condensed must
be allowed
movable
gas
Ln like ities
may
The
in most nitrogen
will
It might
are
to its
commonly to obtain
refrigerants
ice
(-78.
triple
obtained a partially provide
by cooling
be’tter
heat
be touched
in handling
dry
liquid
are with
at the melting
transfer
xl
from
the
necessary each
to effect
trap
to time
com(e. g. ,
Liquid
commonly
than
Hg).
mm
-
and distilling
materials
gases
96.4
and ice
volatil
temperature).
nitrogen
a suitable
Ilslushll
trap,
on liquid
ice,
re-
useful.
times,
are
lower rare
packings
easily
on briefly.
(O”C)
of
in traps
of trap
of the volatile
and ice
by
removal
It is often
at dry-ice
sat-
be warmed
temperature
cold
bails
very
differing
several
beads
steel
of some
is often
trap.
behind
should
(-2 10, 9*C,
frozen
cold
temperatures
nitrogen,
cooling
of widely
condensate
that pumping
point
of liquid
transfer
traces
5-C)”,
not be required be noted
As
and to
wool,
proved
may
To
and
area
to be reached
to the other
-ice
Fortunately
usually
to those
C02
refrigerants
dry
laboratories.
evaporation
ice
from
8“C),
another
evolved
steel
to a suitable
remaining
or dissolved
of trap
(- 195.
and neon.
mediate
of C02
subject
nitrogen
into
also
introduction
materials,
limited
and efficient
flow.
heat
by warming
material
rapid
vapor gases.
Stainless
have
that the
gas
are
Glass
purpose.
plugs
temporary
condensate
of occluded
the distillation
initiating
condensed
components
the volatile
this
simply.
of its
contact
materials.
equilibrium
to improve
be separated
the
wool
thermal
slow,
several
volatile
removal
before
be quite
fashion
for
the ,advantage
for
as helium
and refreeze
removing plete
such
often
the more melt
may
used glass
rates
of the
of species
in the influent
flow
higher
quite
the fraction
a large
-
conditions
passage
i~ the ratio
to provide
in it to achieve
Time
phase,
essen
are
equilibrium
sure
conditions,
of condensed
has
currente
pres
is
separation
stream)
partial
material
suitable
a packing
materials.
vacuum
the gas
to its
commonly with
of eddy
always
under
conditions,
sufficiently
constituents
Ass uming
equilibrium with
some
of other
the desired
blow-through
in. ) combined
rather
is feasible
is
condensation
in the condensed
to equilibrium
with
macro
stream
pressure
that
effects
the trap
mechanical
or rings
trap
temperature
packed
that
a gas
vapor
stream
the trap:
speciee
under
the approach
traps
(3/16
other
from
its
pressures
over
the cold
occurs
at trap
improve
the vapor
of the
through
(assuming
species
at which
in the gas
pressures
Lf condensation
volatile
pressure
while
partial
and insolubility gqs
radiochemistry
can be found
partial
complete,
than
gas
involved).
the least
a temperature
less
rare are
that
of liquid
other will
available
than helium cool
it by
Temperatures often liquid
point. than
inter
necessary nitrogen Slush
solid
or
and or
dry
liquid
refrigerants,
-
thus
dry
ice
-78.
5”C.
is usually
mixed
useful
in working
and isopentane,
with
most
quantities
of gas
will
are
easily
replenished
other
temperatures up only
have
activated
surface
variables
on
at constant
adsorbate
are
adsorption
sure
change
with
A number of which
isotherm
for
Brunauer, sorption
which
P/v form
=
reduce
l/bv
s
+ P/vs
a monolayer
,
per
also
(shape
and the nature useful
P/v
P
is linear.
v~
been
at
they
need
in the
“C,
litera
showing
adsorbed
cc STP
Hg)
of gas
and partial
the
heats
among
dependence
and
T
of
v
at constant
Ln experimental
v;
studies
at a series
may
per
relationships
P
determined
relates
of
of tempera-
be obtained
if desired.
of adsorption
and the pres
of the isostere).
been
used
to express
Langmuir
from later
derived
v
is the
for
in the case
cc STP
of the adsorbate
derived
considerations.
equations
= vsbP/(1
of adsorbent,
adsorption
first
theoretical
Is equation
the extension
mm
it and
extents.
as
functional
P .
because
unit mass
the amount
expressed
-
of adsorbent
used
per
differing
relating
usually
have
where
often
of the ad~orbent
Three
in nature.
gram
particularly
for
such
traps
where
capacity)
relationships
be written
temperature
versus
most
to Langmuir may
since
number
material
at constant
adsorption 27 and Teller
isotherm
large
to be found
to widely
Isosteres
T
equation
empirical
most
1) Isotherms
monolayer
Emmett,
hfierbolic
-130
which
or ice
ure, i. e. , O“C and 76o
the other
temperature
are
has
of temperature
and
of equations
gases
v and usually
2)
are
-Clapeyron
ice,
Of the large
the adsorbent.
v
data
of rare
and adsorbent
of interest:
these
through
operations
adsorptive
called
the isotherms
Clausius
most
gas
and Press
relating
From
The
n-pentane,
“Slush- cooled’l
for
on charcoal
temperature;
3 ) Isobars
tures.
adsorb
over
dry
be reserved
charcoal
is a function
these
nitrogen,
(largest
of adsorbent,
of the gas
traps
on the line.
techniques.
area
gases
adsorbent,
liquid
of separations
Temperature
pres sure
-95 *C,
Techniques
available,
a given
(Standard
P
at
of heat.
adsorption
unit mass
and
amounts
the rare
to refrigerate
usually
the majority
the largest
For
acetone,
gases:
in place
employed
materials
gram
with
and Adsorption
By far
per
flow
may
small
Adsorption
rare
convenient
traps
because
refrigerant
- 160”c.
It is usually
has
a slush
of cold bathe may be found in most texts where vacuum 24, 25 discussed. The author has found the following baths par -
are
titularly
ture
to provide
Discussion
techniques
take
with acetone
and
tbP)
,
12
multilayer
= vfi(vs
of adsorbate b is a constant
“and adsorbent.
or perhaps
the hyperbolic 26 ad-
of a monolayer. P
more
The
–v)
required
, or to
dependent The
of data by interpolation
At low pressures,
isotherms,
since
last
on
form
the plot
definitively
is of low
-
it is found
v,
a linear than
plot
l/b,
of
or
law with
that adsorption P versus
v much
k equal
and
equation 2 for
handy
tabulated and as
reference.
in Chapter expected
creasing
order
LeChatelier
increasing
as
other
volatility
the boiling
(extent
points
Table
2.
tends
Adsorption
constants v
= KP
surfaces, is
and
considered
its
3)
indicated
by the fact
of condensation
over
wide
therm)
ranges
for
constants
models
used
of van der
that heats
values
2)
condensation
releases
decreases
with
Ad~orption
gases
tends
to increase
are
heat in-
increas
-
to increase in the
same
in terms formation
forces
of the
constants often For
to the literature on the subject 23 or to S. Brunausls 8 in Dushman
same
generally
(as
related
of adsorption is referred
13
on physical
may
in is
to the conform
However,
discussion
book
involved
in adsorption
isovalues
to the physical
the
reader
of a gas
the hyperbolic
in the equation.
not easily
type
of
on plane
comparable
isotherms
equations
1) formation
Adsorption
resulting
Experimental
derived
are
are
of:
of multilayers
pores.
Waal’s
gas ,
of the
in the derivations.
0.950 1.0 1.0 0.711 0.885 1,0 0.574 0.692 0.77
in small
of adsorption
a given
obtained
krypton
1/n
of the interactions
to theoretically
thus
in Table
on charcoal
for argon, 1/n
adsorption
surface,
magnitude
for
Euitable
of the
a key
capillary
The
heat
discuss
on the
the result
condensation.
given
process
0.500 0.0764 0.0581 2.927 0.497 0.340 15.99 2.458 1.583
,
treatments
of adsorbate
where
of argon,
K
0 -80 -18 0 -80 -18 0
Theoretical a monolayer
in cases
of the gases).
-80 -18
Xenon
in
of gases
constant.
of different
less
to Henryrs
in the Fr eundlich are
adsorption
T “C
Krypton
constants
a number
of adsorption
and xenon:
Argon
plot
These
remaining
Adsorption
much
the adsorption
adsorption
IS principle
factors
pressure.
for The
.on
(semi-empirical
on a log -log
the
P
reduces
equation
temperatures. data 23
that for
isotherm
studied
and calculated
at several
and interpolation
be noted
parabolic
interpolation 28 and Weil
Peters
8 of Dushman.
from
decreasing
linear
Adsorption
temperature,
es with with
data
(v = kP),
It will
Freundlich’a
on charcoal
their
law
v~ , the hyperbolic
than
to bv
xenon
from
Henryfs
v is possible.
less
s“ nature) is often useful for 1/n . it is obeyed: v = KP krytpon
obeys
in” general
to Chapters 29 adsorption.
and 7 and
Some These
comments
are
mostly
ous
materials
ods
of preparation,
from
heat
in the absence
than
carbon
with
steam
the order
on the nature
from
two
of air
as volatile
materials
1000
square
to the nonporous
surface
area
gram
particle
size.
resides
that
therm, coal
give has
so over
is dependent
Charcoals
low adsorptive
capacity
out more
pores
(perhaps
both
reaction
is endothermic,
then
depend
to diameters processes
that
the history
of its
through
a mafimum
will
surface
includes
many
accommodate
molecule.
as jhe
not be increasing
referred
to as an allotrope
percents
of carbon
other
elemente
It appears surfacee
likely
but are
to some too
the adsorptive in the
same
of carbon, less
thh
principally chlorine,
surfaces e urfacee
small
capacity
ratio.
modified
lJ+
adsorption
the
One
markedly
ex-
on
can in fact
capacity
going
the distribution to molecular extent. for for
analyses as
ash
some
a slightly
has
may
occurs
by the presence
of pores
dimensions,
Thus
various
and oxygen,
and inorganic
on which
very
and eometimes
hydrogen
as
in the laboratory
Charcoal
but elemental 100%
are
that the
comparable
molecules
activation
Since
) still
essentially
activation
but also
the adsorptive
be expected
porous
is possible.
Excessive
sulfur,
but hydrocarbon
for
than
diameters
of pyrolysis.
or to enlarge
adsorbate
he receives
proceeds.
of a char-
consists
new pores
used
iso-
generally
(though
control
in preparation
molecule
always
present
of nitrogen,
temperature
it creates,
on charcoal.
of coal
and activation.
may
activation
therefore
amounts
is widely
of the material
with
a given
During
open
It
structure
of activation
to either
accommodate
activation
effect
pore
pyrolysis
will
ueed
area
sieve!!
after
of
apparently
the hyperbolic
grades
.Steam
and better
pyrolysis
more
as to size
which
occur).
on materials
remove
a Bimolecular
in order
the properties
not only
material
size,
dimensions.
and the conditions
and certain
specific
the surface
independent
adsorption
potential
and the process
material
existing
pects
The
large
Thus
in charcoal
to obey
material
nutshells
porosity.
monolayer
The
the starting
area
(of as
particle
to� molecular
be expected
ranges.
whose
is almost
surface
activated
porosity,
size.
of the average
charcoal
principally might
hardwoods,
the highest
function
comparable
wide
on both
from
of burning
expect
black
and
other
of charcoal
high
-
meth-
shells
is then
area
particle
while.
ntimer
and many
coconut
material
ae lamp
are
of the elements
due to its
small
of the
with
surface
is
such
most
on charcoal
and does
gram)
of activated
diameters
one might
adsorption
per
is a marked
surface
with
resulting
of extremely
Furthermore,
in pores
follows Thus
black
the specific
part
specific
be worth
There
be prepared
start
absorbents
is the result
of lamp
whereas
meters
may
one might
large
may
charcoal 30,31
the greater The
.
The
articles.
charcoal
to remove
at 7OO-1OOO�C. of
of activated review
which activated 32 For example,
opposed
per
recent
pores
larger
species
may
in the past indicate low as
been
atom
757..
The
but appreciable also are
be preeent. not carbon
of oxygen
and
traces
of other
likely
elements.
charcoal
physical
properties
that this
does
tive
properties
that
even
tion,
adsorption
varied
a range
coal
for
both
use
sites
are
very
whose
accumulation This
through
further
gassing
in vacuo
judged
of five.
“’”
years’
may
process
One
may
differences
should
prove
useful
arations
to point
of species
chemists
who
analogies
are
even
mind
--
adsorption
stated
earlier
on particle
size,
(per
through
cracks
The if the ad-
quoted
in the
charcoals
early
at room
to produce
experience
may
in systems a quantity
it is necessary with
be
built
of char -
ways
with
to achieve
expected
ion
is out-
less
as
manifold. of gases
basically
such
the out-
Hg or
adsorbent).
resins,
using
resins
through
It may
similar The
to sep-
many will
that
with
radio-
note
close
considerations
rates
of charcoals
diameter
adsorbate
in the particle
does
of adsorption
will
increases
to the gas
15
kinetic
is not an instantaneous
capacity
particle
cites
are
the material
used.
of gas
which
mm
system
other
exchange
be designed
presented
along
10
of the
Laboratory
separations
(or any
techniques
a stream
is
as water)
satisfactory -4
char-
of residual
(such
to change
proved
Radiation
separations
amounts
properties
in the vacuum
separations
must
small
to outgas
materials
as
has
the pressure
using
adsorbent),
adsorption
which
the adsorptive
and pores
adsorpso critical
of separa-
expected
the adsorptive
gauge
such
in the average
gram
to reach
from
but it is
A reduction
surface
until
in solution
that
he sees
that
adsorbed
on charcoal
procedures
in loss
on seven
purchase
At Lawrence
out that
not
in detail,
of separations
uses
affect
in various
in the various
Separation
Ln order
of samples
vacuum
familiar
those
not be so extreme
continued
operate
result
and preparations
A routine
in the adsorption
The
usually
to add
needs.
adversely
by a thermocouple
UH hasten
not be surprised
of xenon
successive
at 350-400°C.
routinely
from
and to remove
activation.
will
to originally
contamination runs
are
the prQcedure
the course
wise
Let
and
of charcoal adsorbed at a given pressure 33 These charcoals were of course chosen
.
accuracy
many
pretious
charcoal.
gram
chemical
as an adsorbent.
should
differ
whose
limits.
systems
affect
in materials
fair
to prevent
from
is
per
and between
gases
gassing
charcoal
it is probably
Before
wide
of two or more
characteristics
with
dates,
usefulness
of the adsorption
as a factor
sufficient
coal,
of his study
of adsorption
at later
its
certainly
of differences
to predict
rather
factors
the amount
as much
within
out that the experimenter
In one
on the ba,sis
used
like
of substances
in separation
variations
properties
temperature,
order
that all
a class
impair
charcoals
such
is to point
sorptive
vary
not really
variations
literature.
is thus
may
of
though
intent
ent.
implies
not identical. Activated
was
This
phase
molecules interior.
the
process.
It
not depend be so dependexterior
and shortens must
in’
paths
diffuse
Approach
in
to equi -
librium
conditions
creased
contact
is necessary flow,
time
In flow
systems
occurring
thus
est
and
long-range
factors
procedure where
that
these
necessary Most
rare
of interest
problems
arising
variations,
steps will
than
slow
from
processes
in actual
In their
early
and xenon
resorption
could
on charcoal
at
and then
fer
them
may
to a gas
speed
buret IIpure!i
and separation
of adsorbent adsorbent calculate
and of each bed
distribution
Peters
of all
may
minimize
temperature
all
and Weil
by total
adsorption They
10CC STP
the trap
of each
and more
adsorption
steps
deaorption in detail
pump
--
but
on”the
each
lift
but laborious phases adsorbent.
16
after
by fractional
on 38 grams and desorbed p~p
to trans
at which
each
a compromise
at -93 ‘c,
knowledge
that argon,
the mixture
used
by a ToepleT
somewhat
initially,
before
was
temperature
backed
of argon
From
showed
followed
Temperatures are
removal
adsorbate
28
adsorbed
gas
to a suitable
measurement.
and gaseous
of the gases
one
separation
charcoal.
in a straightforward
in the adsorbed
adsorption
in subsequent
separated
be typical.
is equilibrated
not be
temperatures
activated
of the others
factor
at O“C would
total
By treating
gases,
diffusion
for
be under-
of sample.
(roughly
raised
a mercury
be desorbed
and xenon
gas
- 190” C
using
be
the
Procedures
or may
manner
of the
kinetics which
it should
of sample,
10S ses , since
the history
on rare
from
of charcoal) the gases
loss
this
and the
desirable.
with
lower
be necessary.
affect
work
in vacuum
by using
to reduce
may
under
introduction
kinetics
really
affecting
but may
-
inter -
empirical.
factors
be quoted
trans
of these
is
as the Detailed
commence k
of heat of great
the kinetics
changes
trap.
non-uniform
one tends
not result
will
in an adsorbent
should
manner
krypton
separations
make
the rate certainly
conditions
may
at ele processes
as possible
the separation,
considerations
and adsorption
adsorbent in this
for
such
sizes
the bed
insofar
succeeds,
in places
to gas
not be maintained
to design
the kinetics
particle
sufficient
gas
in detail
A compromise
the adsorption
it is
the extreme
Thus
may
affecting
approach
and in-
resistance
enters
from
Although
to improve
to determine
other
the gases
release
Lf the experiment
are
should
of heat
beds
if the gas
size
rate),
in high
adsorbent
and faster
and charcoal
flow
result
to understand
satisfactory.
rates
will
and conditions
practical
particle
(decreased
size
respect.
usefulness
not varied is
flow
rates
are chosen
smaller
the refrigerant
in this
is tried.
usually
stood
important
with
temperature
with
the more
experiment are
low
Flow
is hi,gh.
are
Design
particle
or if the rate
fer
processes,
improve
the adsorbent
small
equilibrium
temperature
thus
with
as too
in thermal vated
should
gas
between
krypton
at -800c
of the isotherms,
amomts
and the volume
with
which
the
of the Toepler
pump
one
could
fashion each Even
the composition stroke,
cursory
-
assuming examination
of the uniform of the
isotherms duce
suggests
gases
the limit
are
obtainable
It might
be noted
a system series
system
rare
uranium
later
mass
traps
waa
they
point
charcoal liquid traps
out,
densation
silica
today
rather
column,
a charcoal
bed
sample a flow 2)
of Peters
on a
helium
and
and xenon
isotopes
gases
a series
and
of many
by what
may
involve
Rare
gas
solid
Methods one of three
of the gases of slightly analysis
to be
adsorbed
of operating
separated
is adsorbed (eluent) of gas
17
the
determination gases
by elu -
in the He and Ne 36 will serve as
will
be made
separations which
a stream
at one
or
of gas
as
moving
gas -solid
columns
will
in which
genera
end of the column
up through
containing
and
a sta:
of liquid
a stream
development
set
here
involve
be classified
chromatographic
gas
in “which a stream
used book
end of an
through
the rare
involve
would
1 ) Elution
categories:
carrier
gas
remarks
on charcoal and thus
above
and as an up-to-date
Chromatographic through
con-
chromatographic on one
later
chromatography
adsorbent
mentioned
in his
recent
pressure
to avoid
eluent
separated
to use
charcoal
at reduced
termed
of some
As of
advisable
nitrogen
Glueckauf
Glueckauf21
gel.
potentialities
of a sample
a few
silica
to refrigerate
be generally
Only
ont~
it seems
than by the method
of gas
of solid
air
in liquid
Keulemans’
separations
column
it was
and of
passage
references.
or
in which
hazard
of the atmosphere
cited.
an experiment
and to operate
In fact,
subject
to
liquid
adsorption
rather
mentioning
cooled
and Weil
mentioned.
to the
a packed
Frontal
separating
of
. 1s worth
or oxygen,
of breakage,
column
of liquid
into
air
itself.
references
moves.
liquid
in the trap
already
of literature
fall
and desorbed
of the explosive
of this
trap
contents
chromatography. ally
pro-
the operation
of krypton
28
from
because
and subsequent
tion
journal
used
separation.
and Xe
an introduction
performed
Because
usually
of the Kr
through
may
100 are
radio chemistry.
procedures
and Weil
to a charcoal
replaced
These
determination
was
than
air
to achieve
tionary
manner of about
on the separated
In these
They
in case
air
been
adsorbent
gas
gel
techniques
techniques.
source
for
yields
quantitatively
oxygen.
of liquid
The
some
a system
of Peters
of safety.
as a safeguard
from
factors
adeorbed
measurements
analysis.
adsorbed
and liquid
column
such
the relative
by volume
in the work
introducing
have
successively
and used
spectrographic
nitrogen,
when
in this
separation
required.
out a matter 222 that Rn
shown
are
to determine fission
A sidelight point
performed
pure,
in the determination of their abundance in air. A simi35 used for the Heparation of argon, krypton and xenon
later
in an experiment from
gases
traps step
was
99%
not be satisfactory in most 34 analyzed mathematically that Glueckauf
in which
as the final
separations
around
and would
of charcoal
neon lar
that while
which
the
and
the column.
sample
mixture
is
continuously
which
the
uous
passed
sample
flow
mixture
initiated
sample.
of bands
enough
in their
each
addition
in pure
to the mixture of pure
diluted
with
carrier.
sorbed
also
breaks
ed with
all
Only
of other
displacer
emerges
.
(thermodynamically ideal
non-ideal
chromatography
and nonlinear very
large
nonlinear.
amounts
, among
in his
linear
-ideal
insight
into
on page given
are
between
with
Thus
for
a single
occurring,
of his
book.
in the pure
is possible. separations Ilidealll
-ideal
and nonlinear 38 Linear of investigatorfl , 39-46
and by de Vault.
non-ideal
adsorbate
will
case, of the
well
the least
of
qualitative
treats
of the reasoning
accescase
useful 36
in-
be con-
simplest
provides
be
as the
be considered may
Keulemans
~
usually
to be non-ideal cannot
theory
47
and Sjenitzer,
isotherms
likely
account
of
and the process
Linear
however.
A brief
bands
of chromatographic
often
The
com-
be obtained
components
the radiochemist
the nonlinear
same
Eventually
adsorption
treatment.
chromatography
may
by a number
is also
the
ad-
saturat-
of the species
pure
in the
least
a mixture
37
the phases
things.
the processes
112 et seq.
involved,
to the
have
by Klinkenberg
chromatography
other
gaBes
in
component,
is completely
or nonlinear,
treated
first
development,
I’non-idealll.
been
gas
adsorption.
of fairly
by Wilson
adja-
this
case
w-ill be
here.
constant is present ~ection,
of gas
theoretical
Consider
phase
has
separations
to accurate
or
treated
is next
component
containing
chromatography
of equilibrium
stantaneous
sible
non-ideal
Gas -solid
attainment
cerned
were
and effluent
is linear
reversible)
chromatography
which
as to the details
isotherm
from
sample
the column
with
differ
carrier
results
recovery
predictions
as the adsorption
eluent
analysis
of increasing
the
to obtain
adsorbed
adsorbed
by zones
Partial
by pure
In displacement
in order
conditions
frontal
of the least
separated
of course
of an “unadeorbed”
so on until
components.
(diluted
proper
the component
and
in the
from
of the least
and the influent
emerge
Theoretical vary
Eventually
a sample
bands
gases,
“and then
any of the gaees
If the components
separated
consists
of sample
through,
sample
the components adjacent
as a peak
of gas
carrier
components
position. pure
form
in
and a contin-
emergence
components
under
development
column
than
adsorption.
it is possible
If the stream
emergence
adsorbed
in the eventual
increasing
adsorption
component peaks.
strongly
of the sample
of their
Displacement
at one end of the
results
or l’peaksi’
in the order
cent
more
development
eluent)
3)
the column.
is adsorbed
of gae
Elution
column
through
an adsorbent
diameter in some it will
and at conmtant small
distribute
and a fraction
uniformly
( 1 -~)
cylindrical itself
packe”d
into
temperature element
throughout. of the column
so that a fraction
on the adsorbent,
3.8
a cylindrical
As
of
If an ads orbate taken
o of the total a fraction
column
in cross
-
is in the gas o of the adsorbate
is in the gas
phase,
with
phase
the gas
of movement rate
F
and
F ,
of adsorbate
of eluent
weight and
Let
gas .
us call
gae
conditions
may in the
CPa Ge)-l
.
A
same
As
k will
in any element
of adsorbate
(C G -1- U).
In most
simplifies
movement tration band the
to
is
and
C
and equal
is
flow
of total
0<<
rate
everywhere It follows
shape
case
rate
does
will
the
F
The
so that
of movement
-1
rega’rdlese =
Ptot
column is total
rate
of
= q L/Ptot
this
expres-
of “adsorbate
regardless
not change
.
k may,
is the
G Ptot)
rate
weight
V/Pa
be
L
above.
G) >> 1,
the column
that the
and the band
of total
column
1 (q L/C
be
(1 + kA/CG)
space,
defined G)-
In either along
will
case
~ .
of
= (1 +vAe/
Ae/Ge
minute, void
for
fraction
+ vAe)
of
of eluent
(kA/C
factor
to standard
in which
per
~ the
of adeorbate
The
The
in the
column
or
1,
sure
Ge
case,
flow
Ae
Furthermore,
linear,
is the constant
Ptot.
and
to the ratio
In thie
in cc STP
the rate
calculate
gas
Hg).
everywhere
linear
cc
mm
in the column,
flow
may
pres
the ratio
OF . ( 1 + kA/C
instances
OF = q L/kA
of adsorbate.
of the concen-
of all
during
its
points
in a
travel
along
column. In ideal
chromatography,
of a band
ing constant in the gas column
where
of adsorbate
column entering
fa
on the
t is total
is just
nonlinear, formula
temperature
la
is thus
in the
temperature. appreciable
gas
present
and constant
is
By
one
of flow
= OFt ,
approximation the
the above
la
pressure
.
case
if
and the isotherm
discussion
is
of a second
of the first. 19
of adsorbate
phase
strictly
adsorbate
for may
in a band
Pa
t ,
isotherm
if the isotherm for
to tbe
+ vA/Pa)-l
of a linear
Even
in the band,
assum-
introduced
adsorbent
case
exten-
column,
= (q L/Pto~(CG
expects
in this
column,
the
ads orbate
plus
In the
everywhere
entering
concentrations
at ,
in the gradual
down
total
phase
arrives
as one intuitively conetant
results
partial
equating
in minutes
a useful
All
analysis
concentration
in the gas
column,
time
(v/Pa)
frontal at cons&nt
the column.
to the amount
of length
stant
is the
is then
constant
is the same,
sion
this
Hg,
of adsorbate
packed
constant.
that
temperature
X 76o
moves
the linear
of adsorbent.
o = C Pa Ge/(GPa
temperature The
G
in mm
movement
G
law
q is the gas
in centimeters,
gas pressure
sion
at constant
where
K
be
one
ie the partial
v if the isotherm
concentration.
G“Ptot,
‘length
all
laws,
gram
volume
space
to as the Henryle
and is the same
then
is uniformly
void
for
Pa per
= 273”K/(T. will
follows
o times
to the moving
of Hg at column
of column
to total
be constant
be referred
q L/C
C
phase
the column
of adsorbent
e .
cc STP
in cc-mm
be called
It then
gas
available
in the element
in and thus
is just
the perfect
in
resides
the element
the volume
adsorbed
gas
molecule
on the average,
Assuming
volumes
adsorbate
adsorbate
through
Ge
of adsorbent
v the amount
converting
the
a given
o of the time
is
constant.
This
P
is known and cona is known at column
a single affect
adsorbate, the adsorption
as .
In many ner
experiments,
corresponding
ponents which period and
containing
are
helium
Kr
at suitable
stance
1,
length.
for
adsorbates
overtake gence
as is
-ideal
usually
=b(vs– v). a surface covered
of the es.
It will
centrated suit
be seen regions
if one has
sense,
region emerge
earlier
than
concentrations
lie that
Departures longitudinal
from
of the bands
linear
gence
first
then tail
a eteep in which There
ment
-ideal
the
for
where
be
must emer-
fz
is
L = 12k2~kZ
the
–kl) may
be
of
front
25),
ideal
from
the emergence
the fraction v/Pa
conditions tail.
time,
the peak
rate
the re -
low pressure front
of the peak
of the isotherm,
con-
In a prac-
the linear
portions
decreas-
and the more
and a long
k obtained
region
(that is,
appreciable
Assuming
sharp
vs
is hyperbolic,
v increases,
In the latter
1! such
and their lead
peak
front,
during of these motion
tail
will where
of movement
due to appreciable
a less
steep
will
effects
approaches
20
can
shape,
bands one
main
peak
give
might
between
useful
emerging
rigorous
qualita-
Thus
non-
earlier
expect
increases back,
of
in a nearly
cases.
approaches
to more
rates
transfer usually
concentration
s lowly
of chromatography.
mass travel,
in the various
to peak
adsorbate
concentration
two general
their
to asymmetric
As
in which
as those
or non-instantaneous
Superposition
conditions.
adsorbate are
a value
of bands
conditions
of a region main
can
band
of two components
toward
as
faster.
a very
in the gas
fashion.
under
move
“ideality
in broadening
non-ideal
than
of movement
is the time
the isotherm
becomes
increase~
linear
symmetrical
linear,
Thus
calculated.
tive
pictures
length..
emergence
Thus
separation
charcoal,
adsorbate
to estimate
in the
component.
v increases
calculated.
diffusion
result
as
with
used
of the isotherm
approximate
phases
band
T
requirement
be less
+ 12 = L,
Kr with
sub-
the rates
of the first
where
T OIF = T 02F
with
o thus
in a band
is an emergent
tical
with
must
the
adsorbed
column
of
the rear
a long
case.
Thus,
that
a minimal
elution
Thus
band,
in which
the case
v/P
of krypton
over
in
receptacle
of least
the
so that times
adsorbed
length
in the linear
If,
02F,
band,
highly
column
than
separation’by
of the second
of the more
achieved,
introduction
of the band
and
cases
com -
chapter)
is complete,
a suitable.
of the band
to be achieved
of the first
is the minimum
then
OIF
separation
the front
width
length
In such
the length
subsequent
are
For
of the rear
band
is that
into
of the
last
column
of the sample
by elution
temperatures.
the final In the
column two
column
1 (see
to a charcoal
the admission
in a man-
separation
subsequent
Led Procedure
is admitted
at the end of sample
in Procedure
calculated.
Xe
and recovered
operation
be less
with
De@i
and
is accomplished
introduction
analysis,
After
separated
satisfactory
sample
development.
is an example.
Xe
for
to frontal
by elution air
the
than
the emer slowly,
and finally
a long
zero. theoretical
treat-
-
The alent
‘Iplate”
theory
theoretical
species The
treats
platesti
corresponding
distribution
the column
in each
of which
to the ratio
coefficient
as
of their
is a ratio
a series
of juxtaposed
a separation
factor
distribution
“equiv-
between
coefficients
of concentrations
two
is achieved.
in the two phases
for
a substance. The
“rate”
convection them.
The
their
theory
solution
variables)
with
is then
Both
be
highly
radioactive
improved. move The
tail
In the high
Mev
The
tors
theory
much
to move
column
and
as independent
ass umptions,
The
journal
of both treatments. 48 deals with by Glueckauf
that as the
faster
need
It the
per
the nature
of an equivalent
flow of the
rate,
adsorbent
eluent
gas,
relatively
of the
The
simple. will
find
peak.
of krypton
and 1-
of column
development
effifac-
and outlet of the
of the results
who plans
study
to
with
) on various
application
radiochemist
certainly
there.
exposure
COIUmn inlet
the
complicated,
main
irradiation
plateli
size,
Although
etc.
the after
dependence
theoretical, particle
fairly
chromatography
with
by previous 49 gram).
of the band
o is larger
charcoal
that the adsorption
watt-hr
predicts
portions gas,
up”
to use
to be unaffected
up to 1350
latter
of the active and “catch
has
be noted
found
theory
is often of gas
concentrations
the
accounts
by passage
mathematically
to make
of the theory
inter
-
and profitable. one actually
However, build
qualitatively
it. might
was
nature
use
e sting
a system
the
useful.
The
departure overly
assumption reality
simplified
actually
determines
in mind
it with
the equations
from
rare
a bare The
a problem
a minimum given
the adsorptive may
vary
involving
for
for
properties by factors
21
these
are
case
charcoal,
may
and For
prove
a cormiderable
recorded
conditions.
to
written
and effort.
-ideal
or more
the theory
separations,
is of course
of his of two
gas
of time
and the treatment
even
with
paragraphs rare
the linear
conditions
cases,
respects
acquaintance
following
expenditure
earlier
of linear-ideal in most
in some
that these
,only
gases.
who meets
to solve
purpose
needs
to separate
radiochemist
who wishes
keep
tend
eluent
becomes
to practice
this
say
warmed
(doses
as
as
to desaribe
and shapes of peaks when the adsorb ate is a 85 are sharpened and separations as Kr . Peaks
such
fields,
“rate”
pressure,
for
that one article
(i. e. , the ‘fheight such
simplifying
include
the radiochemist
on charcoal
ciency
various
noted
might
thus
electrons
along
such
equations
on movement
that
radiation
processes
differential
distance
earlier
regions
would
event
xenon
involve
gas
One
through
the physical
(in the ads orbate
and axial
given
specifically
of heating
account up partial
essayed.
to theory
effects
sets
equations
time
approaches
references
into
and
of these
derivatives,
might
takes
and diffusion,
earlier
Unless
one
he must from
is
quoted
also values
in the literature. erature
for
The
Kr
temperatures
and
author
Xe
(such
is in fact
unaware
at temperatures
as
- 195”C)
must
lees thus
of adsorption
than
-80°C.
be estimated
data
in the lit-
Isotherms by rather
at lower
dubious
ex-
trapolations. The adsorbent
distribution phase
written
OF
.
q L@~t.
out impairing the of
linear
rate
10 cm/sec
Column
impaired
at very 1 cm
flow large
or less,
fully
(e. g. ,, Detailed
density that
of charcoal
extreme
various
satisfactory
addition,
L/A
Columns above
are
the
to outlet
magnitude partial about
over
the
accessible
O. 1 at 25”C,
over
pressure
of eluent
constant
desirable As
atmospheric
mm
Hg.
a certain
v/Pa
for
= k
which
generally will
ranges of
.
column
one may
at which
the band
velocity
of an adsorb
suitable
retention
time.
ate
22
column
in the case
several
Thus
for
guess)
of interest
with
Kr
at
some
is such
decreasof
1 mm
gram
at -195”C. find
are
temper-
orders
per
in
of a linear
rapidly
vary
generally
flow
pressures
adsorbate
the
v in cc STP
100 ( a rough
chromatographic
a given
increasee
often
of inlet
difference
the desired
by adjusting
One
as possible
that the ratio
operating
velocities”
system.
sufficiently
and with to 760
in
In
his
to maintain
the values and
flow, close
10.
that higher
temperature
3 at -80”C
an inlet
always
of
required
velocities
charcoal,
a factor
it follows found
constructed
ranges
r~tio
of charcoal,
the bulk
it follows Band
wide
O, 2 gm/cm3,
of
success-
A*
●
to be as nearly
Adsorption
and band
pressure
a typical
over
chapter).
about
as possible.
is
respect.
is a constant.
ing temperature,
unity
function
gram
the desired
generally
been
one has
and it is thus
speaking,
varied
i. e. , by changing
isotherm
of eluent
varying
once
nearly
pressure
roughly in this
~tis
column,
out outlet
with
O, 5
per
with
is also
by only
varied
to sustain
be as near
conveniently
ature,
rate
length
differ
operated
Thus
of the
column,
preferable
most
often
flow
length
inlet
a given
will
pressure
pressure
between
are
most
the linear
along
columns
at the outlet.
wishes
range
is not conveniently
atmospheric
pressure
in the
in last
serious
value
are
have
for
is not par -
Efficiency
diameter
with-
of the order
without
diameters
be
value
rates
the optimum
flow.
of the may
at will
parameter
is not a rapidly
given
column
flow
this
Column
centimeters
lies
of L/A,
be varied
of two or three near
1,
in favor
movement
an optimum
Linear
linear
efficiency
generally
values
rapidly
Procedure
may
though
decreased
of several
of band
predicts
by factors
diameters.
Again,
and columns
theory
the column,
less
be heavily
rate
quantities
typical,
drops with
column
diameter, used
Thus
be varied
than
generally
so that
of these
be considered
efficiency
linear
all
through
and may
increased
around
of gas
will
systems
efficiency.
might
critical
effect.
gases
Not
column
flow
titularly
of rare
in separation
Hg
are Thus
for
temperature
as to give
a
In addition achieve
initial
improve
sample
,9eparatione
proportional roughly
A few
or borderline,
ditions
may
system.
with
In the
latter
be made
caee,
length
(C G + vA/Pa)written
troduced
coal
column
centimeter
length.
gram
of charcoal,
as
Detailed
Procedure
radioactive length
margin
foregoing
Kr,
of safety
variations the gas
from entering
partial
thus
isotherm
however, of a very
being
of
of
Xe.
values
10 greater
Let
Under
= The
of for
using
centimeters
sure
a f3-y
1 is about
length
of
Kr
this
form in-
length.
If
introduction,
v
are
Values experimento a char-
in the influent of charcoal
known
sample survey are
gas
per
meter
25 cm,
neighboring
in the
rare
tem-
in
on bands The
of
actual
calculations
pressure sample
of temperature
of the two.
this
col -
a considei-able
that the above
conditions
at
introduction
noted.
as the partial
us assume
23
h
be re -
of adsorbate
is introduced
5 grams
uncertainties
the heavier
may
these conditions is 10 cc STP 100 cc STP Kr gin/cm] = (10 cc STP Kr/gm)(5 an value of v used above is strictly
and
v for
this
temperature.
in air
t~ a typical
same
= (q L t/Ptot)
unit column
of band
few
the
of
of width
under
lKr
for
margin
as proposed.
1.
is not experimentally
allowed
con-
can probably
la
sample
at column
pres
Kr
Procedure
the column.
pressure,
a factor
of
corresponds
in Detailed
per
contains
run to run in suâ&#x20AC;?ch factors
100 cc STP
about
1,
widths
used
column
at
as
cc STP
during
of Kr
the partial
arriveq
necessary
-
of the
in a band
be tried
earlier
the total
is known
introduction.
the adsorption The
gae
one
is unsatisfac
a suitable
= (q Pa t/Ptot)(vA/L)-
100 cc STP
The
given
operating
G G << vA/Pa
the calculation
and that
at the end of sample
estimate
tains
that
Hg.
where
eimply
If the adsorption
perature.
umn
â&#x20AC;&#x2DC;C,
at O. 02 mm
given
is constant
for
Assume
at -195
constant
2 cm
required
was
la
prove
on the adsorbent
if the isotherm
quantities
accessible.
cc STP
is
may
in es -
are
runs.
case
as
length
of adsorbate
be determined
tally
per
by the
pressure
trial
band
approximation
divided
which
few
the usual
that the band
the partial
of other
changes
with
might
are
construction
of sample.
the system
length,
of a very
and for
1,
retention
perform
and/or before
to be satisfactory
usually times
column
operation
parameters
to
increases
one might
directions
initial
of an adsorbate
to a close
it is obvious
is
further
on the basis
which
length
will
retention
broadening
that the proposed
appears
to column
band
column
length
since
chrornatographic
column
regards
adjust
in column
while
in the indicated
as
respect
The
may
then various
may
also,
calculations
indicate
be adjusted
particularly
small
length,
of a proposed
If the operation
safety,
Increases
of prior
calculations
one
components
the column
examples
If &e
velocity,
retention.
the performance
below.
band
of several
to L, 1/2 L .
as
timating
tory
to adjusting
gases
are
Thus
it is
of
and Kr
also
in conâ&#x20AC;&#x2122;
and rare typically safe
to say
that
Xe
till
be initially
retained
Beyond
this,
column
will
be attempted.
able
vS,
the cc STP
to
no statement
100 cc STP unknown,
per
concentrations
Having
retained
separation
ties,
and thus
most
conditions,
to
Xe
with
for
most
length
Xe
may
it is
discussion. be less
than
umn
a few
is,
all
However,
but a few
an unnecessarily in order mated
to bring
moving
Kr
retaining release
time
than
for
in the mode
adsorbed
gas
in other
minimum
the band
width
of xenon,
under
would
be eluted
have
so one raises
the column
column
A sample
development
intro -
pure
a column
the
would
xenon. be take
temperature
calculation
appears
will
off a col-
leaving
left
of Kr from
con-
length
at end of sample could
minutes.
column to the
of operation
krypton
the e lution
of the
be sufficient
refers
be useful
for
with
minimum
“2”
the calculated
Elution
off in a few
earlier
may
Kr
-
under
allowing
usually
k~) where
of the krypton
even
than the purity will
column,
the adsorptive
of the
case,
at - 195”C,
Browning, and
them
Xe
and Ackley
fission
until
products
radioactive
to the atmosphere. be designed
of the theory
used
ence
to a more
ideal
approximation
nevertheless .of the
in general
given
2,
of the less
during
gas
of esti-
in the
second
below.
Adams,
system
the Kr
retention
example
time
are
rare
of magnitude
the purity
fractions
gases
than
introduction.
long
involved
of the
As
obtained,
tailing
component,
rare
percent
the end of sample
of
is the fact
portions
an order
easily
of both
linear-ideal longer
compar-
and by the adsorption
small
by about are
the equation
with
width
are
of each
be attempted.
to be better purity
adsorbed
in the
percent
may
L = 12 k2/(k2–
use
on the
is of the order
complication
the adsorption
Kr.
Xe
of the isotherms
serious
in suit~bly
of this
is greater
the band
That
fore
less
of little
duction. only
,“ because
Although
If k2/kl
Xe
differ
be expected
1!111 to the
nections,
and
separation,
here
which
of the other,
development
The
and
discussed
portions
separations
to Kr.
Kr
of
of air.
velocities,
However
purposes.
and
Kr
sufficient
to achieve
more
the
the band
respect
The
by the presence
by elution
‘Wiling”.
v being
of
a monolayer,
A more
quantities
than the band
disposition
on the adsorbent
be affected of large
of
to form
of charcoal.
their
respect
values
ly nonlinear.
certainly
band
The required
gram
on the column
narrower
as to the actual
but definite
that at these will
in a band
rough
as accurately
detailed
from
have
of course
a useful
predictions
with
is
experiment.
24
reactor sufficiently in this
before
trial.
for
off-gases
decayed
reand
to permit case
Some
“that the
discussion
given
of the theory
illustration
on a system
necessary
as possible
not be satisfactory
provides
reported
homogeneous
the system
treatment
would
recently
species
It was
in designing
50
in the article and a refer51 is noted. While the linear
for of the Fission
use
in design
calculations gases
in this
case,
it
and a comparison
contained
in a stream
of oxygen
flowing
and 25 “C) Each
were
series
Bisted The
at a rate passed
of pipes
charcoal
was
is
thus
l/(bulk
In the
O. 5-in.
1. 50/k
coal
pipe
6 -in.
in the
column,
OF is thus d~8i~:d
=
0.0104 ) of k given
velocity.
retention
times times
and lengths
times
for
were
observed
per
percent
gram
of are
of char-
of the adsorbate
section
the length
equals
is thus
and
TR
O. 08 for
Kr
for
The
Xe.
This
nature
of pipe ~
+ values of
calculated
Observed
article
of Henry’s
for
(in cc STP
pressure).
respectively.
on variations
above
= ~ + ( experimental
The
163 days
liter/rein.
helium TR
write
law
re-
also
con-
constant
of carrier,
estimated (in rein,
the last retention were
Kr
flow,
43-cm.
with
partial
charcoal
).
k as
Using
#
estimated
0.08
for
26 min.
2. 1 and
20 min.
Observed
Kr Kr times
, respectively.
25
and
1.3
T-
K
for
of O. 6 or
-80”C.
Emer-
stream,
=
,
(bulk)
To
emergence
is
cal-
of
1.6 we
density
column 43 gmX760 1600
Xe
time
and
in the tail
temperature,
1 gm/cm3.
deof about
in the case
column
Thus
were
the trials
the effective
retention for
and
times
at about
to be 43 cm3.
the calculated
time
and 25°C
flow
actitity
in all
separations
columns
in the exit
retention
In the article
is
O-C
Xe
gases
eluent
1~0 of peak
obtained
for
rare
of 25°C,
and
were
column,
= lA~t/q.
.aeometricallv
example,
maximum
and
off using
helium
radioactivity
approximations
= L/oF
of the 40 to 50 mesh
temperatures
separations
the linear-ideal
and eluted
16 or 43 cm,
of 5,
peak
Satisfactory
may
ima
equal
in cm/gm
formula
Xe
and
by measuring
breakthrough,
recorded.
Xe
Kr
of charcoal
, and operating
liters/rein. peaks
from
space
a few
of the adsorbent,
end of a column
diameter
gent
20.4k
and the
section
of the simpler
Hg adsorbate
and 60 days data
only
time
for
mm for
of void
and the adsorbent used. 52 recently reported studies of 85 and Xe133. The tracer tracer Kr
using
at one
is
in each
of L/A
and Grandy
on charcoal
ume
of the pipes
pipe.
of the charcoal
L/A
125 X k (days).
1.3
per
content
and coni. d.
of krypton,
posited
culate
10 days
volume
Values
in each
) =
10 days
charcoal
density
the ratio
Use
retention
about
experimental moisture
Koch
1.6
thus
were
temperature,
1 -cm
are
charcoal
are
interesting
time
X 105 X k(min.
gram
that
phase.
Total
bulk
1 cm3
calculate
in the gas
in the article per
roughly
Retention
1.80
adsorbate
pressure
one may
justified.
k
is
charcoal.
l-in. pipe, and O. 00792 for 6-in. pipe. 1000 cm3/min. X 1. 14 cm/gm . = Xk 60 = O. 375/k in the ~%.~ipe and O. 0104/’k
OF
there
resides
by band
tention
As
containing
and 60 ft of 6-in.
internal
in cm2).
pres sure
for
= qL/lAPtot
Similarly
pipe.
in the column
tains
OF
of pipes
pipe,
packing
-section
1 atmosphere
lb of activated
l-in.
the total
O, 285
(at
series
at an ‘average uniform
pipe,
in cm/min.
in the
From
)(cross
O. 5-in.
minute
of 520
40 ft of
one arrives
density
1. 14 for
a total
pipe,
Aaauming
per
two parallel
contained
at 25°C.
of charcoal
to O. 69 gm/cm3. pipe
through
of 40 ft of O. 5-in.
weight
of 2 liters
1.6
volmm Hgxk . cm’/min
min.
of the peak
and the max -
.
The
emergence
by means Keulemans
discusses
technique
involves
changes For
components
radioactive
various
gases
methods
another chamber
of the various
by charcoal
will
in certain
adsorb
interfere
to slightly
of oxygen xenon
are
chemically
from
the gas
of some
from before
the
thus
introduction
from
the mixture
rare
gas
fractions
of convenience
after
gasee
before
their
charcoal
possible
should
gel
has
specific
those
of activated
Adsorption areas
charcoal 28 There
mentioned).
may
adsorption
This
choice
and
are
be separ
-
be removed difficult
to
it (e. g. ,
either
or from
may
amounts
by adsorption
to ‘poison’
their
large krypton
usually
always
they
rare
be removed the
be made
separated
as a matter
experiment.
is the most
one.
Silica
53, 54
the chromatographic
krypton must
since
than
from
before
hydrocarbons materials
elution.
in the particular
Though the only
of rare
it.
and nitrogen
If only
air
from charcoal and their accumulation tends 50 oxides of nitrogen, HCl). Most impurities
water,
other
of argon
from
to charcoal
through
oxygen
chemically.
to separate
Certain
used detects
leaving the column 55 sort to detect the
argon,
separation
light
widely which
impurities
while
to remove
difficult
moBt
gas.
the column.
chromatography
krypton. its
leave
accomplished
or by distillation,
ated
the gas
a counter
Thus
be detected
gae es pas sing
is to paea
extents,
is very
The
(katharometer)
or near
as they
may
of the effluent
method
it is not necessary
Methane
on charcoal
cell
y of the effluent
cases.
is best
of interest
separation.
remove
different
and nitrogen
a column
property
of detection,
components
Ln separations gases
from
in some
conductivity
conductivity
an ionization
activities
change
a thermal
in the thermal
through
been
of various
of the corresponding
less (its
generally
useful
is a very
general
than but of the
use
adsorbent property
same
in the adsorption
ie in particular
one
it is by no means of surfaces.
order
of magnitude”
of radon
other
class
has
as
already
of adeorbents
which
should be mentioned. These are the so-called ‘Bimolecular sieve” ma56, 57 terials, now commercially available from Linde Air Products Company, Tonawanda,
tion
New
properties
Linde
York.
are
Molecular
Thue
uniform
as those
of many
sorption
for
the adsorbent Because
CaO.
size.
diameter, activated
a given
gas
and in fact the pores
A1203.
peculiar
medium
(and molecular)
these
to some
(activation)
porous
4 and 5 angstroms
tion.
is
Their
of hydration a highly
discussed
Sieve
alumino-silicate. water
Actually
are extent
occurs
with
results
and the 4A is that little
in which 4A and
is strongly goes
have
in which
Specific
dependent
through
change the pores
been
adsorption
26
Sieve
in the are
surface
structure.
pores areas
The
at nearly are
lattice
of remarkably
have
on the degree
occurs
is a“ sodium
of the original
reported.
a maximum
such their adsorp23 Thus, the 5A
removal
5A materials
respectively. charcoals
and as
by Dushman.
Si02,
property
The
zeolites
of rotighly as
extent
great of ad-
of dehydration complete
of molecular
of
dehydradimen
-
,
sions,
the
size
adsorption. tive
of the adsorbate
Thus
to one another
sible
illustrate
ane.
On a charcoal
water
considerably
and charcoal. quite
close
ent.
in
ents
It was
keeping
be
literature
IV. The of target
clear
SAMPLE radiochemist
solution
may
produce
likely targets
complete
initial
handle
than
removed H3P04 product.
large
Sieve
(27, followed of all sievell
of the peaks
positions
sieves”
were
using
or mixed samples
absorb-
is worth
radiochernical
procedures
also
Aluminum
as
for
rare
heavy
C-RLERS
gases
the target
Since
the recovery
of solution,
gaseous
from
elements
bringing
products
regards
of the
targets
products
volatile
is
are
a variety
in which
material
acid.
drops
containing found
Thus
of 30%
caustic.
nicely
method
gases done
will
with
uranium
H202
of solution
to the solution
of aluminum.
27
may
often
acid
Methand
easily
again
re -
extreme With
simplify
choice
are
simpler
dissolved
with
targets
for
of
matters.
If the
is to
in con-
and the HC1 fumes
be useful
of small
gases
the feasibility
Solution of uranium in warm 59 and hydrogen is the only in 6N NaOH,
a
procedures
of dissolution.
acid.
is
added
into
to be desired.
encounters
with hydrochloric
satisfactory
dis solves
a preliminary
evolved
fission
of, the rare
solution
products
usually
usually
solution
nitric
a few
This
from
radiochemist
from
with
been
to recover
WITH
for
containment of metal
in a trap
amounts
and the krypton
the solution of spent fuel elements 55 certainly exemplify the most therefrom
that the
those
or as
which
of the two adsorb-
from
such
need
in principle.
to be met
by hydrogen.
er foils
positions
-
-meth-
of Bimolecular
percents
gases
of any
usually
tractable
gases
HC1 with
has
impoe
that the separation
“molecular
of rare
EXCHANGE
the volatile
the products
centrated
ucts
be used
the more
the small
Solution
rela -
off together,
of the peak
AND
suitable
in the literature
problems
available
have most
method
from
of the rare
covery
relative
average
is unaware
may though
#my
reported
came
adsorbent
a weighted that
off first Molecular
found
the weight
SOLUTION
materials,
be effected’
which
that the
of
different
to date.
occurred.
must
then
a mixed
separation
author
came
On 5A
by using
possibility
in the
The
It was
found
to obtain The
in mind.
in the
further
useful
the extent
be quite
and separations
and krypton
by using
calculated
adsorbent.
could
the nitrogen
but together.
by the methane.
to those
may
on charcoal,
the nitrogen
be achieved
the mixture
the pure
(20 “C), later
at 20 “C,
could
influences
species
be feasible. A recent article gives an example 58 The mixture studied was nitrogen-krypton
column
later
gases
strongly
of two
the adsorptions
considerably
by weight)
three
ods
may
the point.
and methane
has
from
on charcoal
will
molecule
the ad~orptions
simPIY 9270 gaseous
no gaseous aluminum clad
prodcatch-
in relatively
Solution the rare The
gases
former
their
must are
with
or adsorption
and active change
from
simply gases
in the
cooling
rare
are
with
.
As
diffusion
phase
and heating
removal
of the tracer
least
complete
exchange
the
gases has
from
been
solutions
studied
tracer
xenon
moval
are
lives
in solution
ium)
for
have
first
hydride
are
chloride
diffusion
negligible. in place
ium
metal
les~
than
containing 62
most
ameters in
before
solution gaseous
might
of the heavier
metal
lattices.
I,microcracksll
fission
products
temperatures
and cracking
rare
may
gases
are
of rare
often gases
xenon
uranium
removed freshly
from
from
in aqueous
AgC104
cupri-
is generwith From
is no detectable of rare
than thus
uranat
begins,
diffusion
as the atomic interatomic
be mainly
the
loss
gases
Negligible
temperature
by
and
potassium 61
is desirable.
there
di-
distances
through
lattice.
been
reported
neat method for removing rare gases from 63 recently. It is based on the fact that long-chain
salts
of heavy
metals
(more
rapidly
emanate
gases
rare
gas es quantitatively
can be swept
from
28
solutions).
be
uranium
be evacuated
evolution
of may
the hydride
at low temperatures
if this
uran-
metal
A particularly
than
other
decomposed
generally
larger
re -
on the formation
Thus
must
the
helium.
of the sample. at room
for
of
with
of hydrogen.
metals
commenced
be expected
Movement in the
from systems
is
At higher
by swelling metals
gases
dissolver
depletion
of various
in saturated
amount
and ex-
out of solution
hydride
dissolves
as helium
half-
uranium
then
“~f rare.
with
less.
from
of uranium
of a small
of rare
Thus
1000”C.
accompanied from
of uranium
Removal such
the
or at
species
(specifically
from
1~~ or
consider
solution,
that the
Efficiencies
and the xenon
Uranium
the evolution
swept
ex-
by alter-
of diffusion)
gas eous
targets
of xenon to be
solution
satisfactory.
with
The
or
often
also
gases law
(as
and half-times
Thus
from
Loss found
carrier
time,
thorough
carrier.
Fick’s
effective.
gases
Amalgamation
and boiling,
boiling
target
was
with
are
slow,
theoretically
minutes.
is also
to the hydride
method.
expected
minutes
rare 60
studied.
inert from
exponential
solutions
at 300”C
converted
ally
than a few
been
as
of a few
removing
the hydride
some
is
through
gases
The
of the carrier
the target
with
the rare
mixing must
and
any chemical
states.
miting
One
from
of carriers
With
relatively
gases
(starting
found
of the order
the clear
methods
by bubbling
It was
of more
Boiling
of dissolved
theoretically
perimentaUy.,60
gases
to venting.
chemical
by convective
of the system). active
in which
before
phase.
physical
are
insured
prior
be effected
between
processes
of parts
complete
stream
on the gas
complete
is usually
or a system
as introduction
may
of exchange
one of achieving
gas
gas
work
gases
performed
rates
system
the effluent
in quantitative
operations
is
out in a closed
the active
no problems
problem
nate
removed
is preferable
exchange
one has
be carried
targets fatty
has acid
and very
rapidly
Removal
of more
than
997D of the 3. 9-see
Htearate
targets
pendent
in fission are
of carriers.
yields
are
of no primary Rather,
yield
The
of gas.
interest
yields
experiment
and one point to reduce
previously
used
procedure
are
ual pressure certain gas
with
partial
behind
to the amount
es to increaHe find
that his
a lower procedure cipal
yield
limit
100
specific is only.50%
losses
Method~ veniently
which
divided
of the type
mentioned
amoonts
losses
a trap
in a resid-
the
and bear
if one obtains
20 cc STP
or a
in which
of ga~
18 cc ST P),
one may
have
by the usual half - life
Muller
been
Incorporation
of the
or” proportional
no
90’-7’. yield
experiment
wish-
of carrier
he may
There
is
essentially
u8e without
modification
(where
are
the~e
of the
the prin-
rare
counter:
with these problems 64,65 Only a few
time
course
the moat
favorable and often
geometry necessary
emit as
means
gas
choice
of this
be de-
will
of counting
of radiation,
in the filling
be made
of absorption
losses.
of low
of activity
isotopes).
of short Both
range Geiger
(soft
beta-emitters,
and proportional
29
involves
one in all faced
to standard
here.
activities
in the assay
levels
of
of a Geige~-
experimenter
be referred
gaseous
level
desired,
The
must
comments
be con-
will
technique
and filling. in detail
may
of method
and energy
of information
use
activities
and absence
radiations
radon
construction
efficient
rare
g as to be counted The
the first
ACTIVITIES
The
of kind
and type
of counter
subject.
to count
considerations
of activity,
GAS
categories.
the problems
on the
R-E
used
several
termined
1)
COUNTING
into
activity,
such
than
of carrier
one finds
than
losses).
V.
which
rather
only
to
of a certain
and in a later
by using
(10
from
Thus
cc STP
by condensation,
of cc STP
added.
when
of the
in terms
stream
of carrier
experiment
less
in a transfer
of carrier,
activity
to the amount
to reduce
gas
percentage
from
in mind
usually sub-
of so many
that most
in terms
are
interchange
be kept
addition
to perform Actual
to something
happens
the
of interest need
considerably
in the exit
cc STP
gases
be expressed
losses
of carrier
with his
are
. concerning
in terms
should
volume
of a gas
of inde-
complete
vary
‘It often may
in studies
one will
expreseed
may
in a given
These
in an experiment
.
rare
of c,arrier
which
pressure
ia condensed,
relation
success
of the type left
are
amount
used
and c~nveniently.
in particular
the
Uranyl
gases
gas
assuming
needs
required
it desirable
for
much
accurately
ones
stearate.
to be made
added
of how
barium
were
rare
comments
of carriers
from
catchers
containing
a few
operations
and activity.
achieved
stearate
by consideration
counting
was
chains
perhaps
Amounts
determined
219
and barium
yields There
sequent
Rn
This
is
texts of
as a result
It is thus
of
desirable
or of active
species
or alpha-emitters counting
for
have
been
used,
each
having
associated
with
proportional times
samples
pulse
vary
voltage
plateaus.
This
but is more with
with
counting If absolute effects
(electric
depending
constructed of field
with
tubes
General theoretical
sion
ically
except
using
ization
aliquots
tubes
Positions brief
may
lengths,
per
till
timum
be determined
construction especially form quench
will
(particularly from
negative materials
unit path
highly
probably
may
using
Some
any
in Ros si and
determined
and thus
find
some
by his
empir contechion-
the wall
effect,
variety
saturated
30
such
as well Purity as
and a suitable
factors
as
in the literature,
experimentation
counting).
A large
gases
on so many appear
electronics
species
Light
of the rare
depend
in proportional
be used.
be
that the average
length,
examples
electronegative
ions , is important.
and
may
an approximate
be found
generally
(remembering
of plateaus
but the researcher
filling
of the filling).
be made
here.
may
effects
by installation 66, 67 voltage.
including
are
end
sample in two tubes of identical 68 and wall effects by a similar
diameters
and shapes
discussion
fillings
effects
walj
Counters radial
type
counting. for
and for
at the proper
effects,
this
absolute necessary
is
with
the same
in the counter
the field
corrections
End
of the same
radiation
are
detection.
and held
and composition
fillings
quench.
which
and wall
effect 9).
of different by the
preclude
over
for
vary
heights
to calibrate
to attempt
of the radiation
time
and proportion-
do pulse
easier
es-
more
multiplications
than
extremities)
required
the wire
different
on pressure
Counter
with
of wall
for
produced
depends
volumes
Appendix
by counting
struction
ionization
Geiger
and to reproduce
than
for
by using the 55 (as Fe
radiation
gas
corrections
at the tube
of end effects
234,
it is much
is lmown
unknowns,
of ion pairs
derivation (page
Staub6â&#x20AC;&#x2122;
specific
as
region
activ-
is to be obtain-
as by running
to both
gas
be found
as accurately
levels
the latter
usual
as say
distortion
active
at least
in this if very
the rare
accuracy
monoenergetic
be attempted,
concentric
discus
As
whose
count~
must
some-
and the
important
method
is applicable with
are
if the best
suitable
if one may
dead-times
containing
some
in the proportional
must
number
and
and discriminator
in as saying
field
on the
the minimum
some
region.
counting
fillings
equipment However,
performing
savings
conditions
accurate
samples
conditions
counter
method
voltage
in the Geiger
of counter
nique
with
since
Since time
can be reproduced
voltages
rapidly
The
counting
observed
al counters,
smaller. case,
electronic
expensive,
of usefulness
of activity,
in composition
to set high
consuming
are
The
and less
range
levels
in any
be run.
conditions
height
x-rays)
more
losses
reproducible
Counting
a greater
high
slow
must
of course
tablishing
is simpler
do have fairly
is relatively
ity will
ed.
to count
and disadvantages.
counters
coincidence
manner many
Geiger
counter~
wish
resulting
advantages
necessary as by his
as
op-
counter
of materials,
oxygen
which
of polyatomic
hydrocarbons
to 68
tend
to
gaseous are
among
the
-
most
copmon.
Detailed
It might
Procedure
purification. (roughly
At Lawrence
krypton,
junction
with
portions
this
gas,
When
low
level
liter
in
2) levels
it may
External
are
be
sion
tubes
on one
counter
lower
counter
best
accuracy
permanently
available
thin-walled
for
e~timated mg/cm2
counting counter
100 to 200 These The
disintegrations/minute
counters counter
were
was
the aliquot
dilutions
with too
used
sealed
reducing
itially
Kr85
inert
of the carrier
with
sample are
which
was
For
higher
re-
being
respect
such
con-
efficiencies
to be described over
the use
The
effort
next.
of ‘! fixed
in rapid
the container tube,
succesin a
which
must
with
volumes
the gas
counted
may
resulted
of 3-10
be accurately
system
by a seriee
cases
where
in an
cc and 30
activities
as
low
as
assayed.
in the aforementioned
a vacuum
for
factors
specific
could
region
for
as in commercially
glass jackets (Radiation 72 used this type of tube
jacket
cc STP
described
with
counting
and absorption
into
gases,
to fit the shelves
Reynolds
with
rare
Practically
counted
71
concentric
samples per
per 85
reduced.
counting
in the Geiger
permanently
be
).
efficiency
of 5-20~0
Thus
Kr
In very
geometry
tubes
may
considerably
geometry
efficiency wall.
70
method
samples
Illinois).
Combined
whose
containers
solid
tubes
Skokie,
d/m
assay
geometry:
of this
of samples
counting
counting
Laboratories, ‘ 85 counting Kr .
proaccu-
beta-emitting
geometryif
to a thin-walled
Counter
smaller
necessary.
and overall
advantage
is thus
wire.
in’ con-
to allow
4200
krypton
reproducible. volumes,
plated
and
carrier
container
by constructing for
in calibration
For be affixed
(say used
for
1958 should
where
reproducible
the ‘rfixed
is that a series
ordinarily
be expended
with
One
or energetic
small
the main
sodium used
date.
or
is accurately
than
with been
at the
and in 69
background to use
in fixed
to fairly
seen: below
geometry”
this
in a thin-walled
counter
limited
isopentane
is desirable
/min.
at an, early
counting
better
to
no further
counted.
the atmosphere.
be necessary
be counted
generally will
disintegrations
for
according with
to be counted it should be borne in mind . IS now appreciable. In the Paris region
of gamma-emitting
to .a thin-walled are
are 85
drying
Hg have
generally
of the aliquot
from
the atmosphere
may
tainers
1200
after
up to 20 cm are
purified fillings
technical-grade
cm Hg pressure
Kr
and correct
of activity
the gas
As
was
of
removed
work
from
level
xenon
counter
ae quench
Plateaus
measurement 85 of Kr
1954
used
low level moved
used
levels
of krypton
in carriers
is
but several
that the atmospheric
and
Laboratory
pressures
quench.
of rare
that krypton
in proportional
Radiation
and xenon
and convenient
this
used
20 cm Hg pressure)
Argon,
rate
be noted
1 are
work.
and provisions of expansions the activity
for and
is in-
great.
At Lawrence ing and following
Radiation the decay
Laboratory of a variety
31
these of rare
same
tubes
gas
activities.
are
used They
for are
countsuit-
ably
filled
permit
and used
decay
particular taining
ing
curves
equal
used,
volumes
.
counted,
sion,
but overall
efficiencies
Each
circuitry,
systems
.
and the
which
switching
arrangement
resolution
of fission
and tedious,
walls
to remove
the
softer
accurate
determination 88 the counting of Kr .
tering
definitely
roughly xe135
decay
curves
that the behavior
formation glass
decay
reached
decay
was
1s “ expected
decay
curves
farther
for
but conducting
is to be counted It was 10~0,
of”interest produced
stated
tail,
in some
suitable
target
in which
he can
in a U235
target
the
same
tor
k in this
tube
later
familiar
and case
for
a known determine
irradiated
efficiency
The
manner
counting
no different
neutrons,
.
provided
counter
simpler
became Xe’33
and assumed
the
18. O-rein.
immediately of local
The for
glass
it wag
with
after
charges
in irregular
sample
matter
was
containers
its on the
deposi-
the internal
the gas
of these
that no effort
accurately.
undoubtedly
to statistics always
that the
be noted
in subsequent
are
are
enclosing
As is diffi-
mg/cm2
and
associated
to be ionized
surface
85m
Kr
200
-
and a
walls
of
resulted pursued
in which
in
no 88 Kr
geometry.
above
efficiency
essentially
a U235
walls
in high
but it should
the actual
dures
a conducting 88 Kr conforming
from
succes
to be counted.
the scattering
85m
that accumulation
to provide
a stop-
point concerning 88 of Kr exhibited s cat-
in the same
curves
hypothesized
As
into
special
curves
the Kr
statistically
the R~8~
“ was It
that
with
and permit
up one
expectation.
in the range
be plugged
in rapid
4. 35-hour
by absorption brings
be-
is provided,
special
of the jacket containing the gas was resulting 88 of the Rb on the walls. It was found that silvering
tion
are
betas This
char -
to and removal
samples
walls
the jacket
of
.
the decay
behaved
As
73’74
with
noticed
of the Kr
daughter.
Rb88
from
still
is fitted
of the tube
purchased
con-
radiation
may
be plugged
were 85m
statistical
when
may
selection 88 Kr
are
which
attachment
2. 80-hour
88
It was
beyond
statistical
Kr
activities
of many
the
y counter
of the beta
a base
easy
With
and
of a mixture
satisfactory
to the jacket
of tubes
rapid
of Kr
various with
to allow
a number
tubes
gives
the counting
allows
a few
for
losses
activities.
Hg pressure
the energy
connection
joint
product
with
coincidence
higher
10 cm
is fitted
To facilitate,
into
initially
with
vary
tube
ball
to reduce
and isopentane
losses
a panel
cult
from
filling
of argon
and ground-glass
vacuum
counters
Absorption
by Reynolds.
the counting cock
to be taken
electronics
acteristics
quoted
as proportional
with
counters
to most rare
are
and the same
of unknown
of fissions
the number thermal
counting
conditions
involves
the number
).
counting
samples.
Thus,
The
has
counting
order
nuclide are
re-
proce
-
contexts
counts
the Kr
been
induced which
by counting
f,
each
fissions
calculation
of fissions
for
in other if one
of the
to determine
conditions
Such
of such
neutrons
was
made
calibrated
radiochemists
gases.
number
counters
is ordinarily
and 88 from
by thermal occurred
the Kr 88
(using
of the calibration
the activity
AO,
of Kr
fac88
extrapolated
back
to a suitable
zero
time(
the midpoint
of the irradiation
for
sufficiently ehort irradiations ), and a suitable aliquot factor. Thus, f = kl X Ao ~ cc STP carrier = k X AO X cc STP carrier/POoC. The actual volume V/ 7 6
‘o “c x
V
of the counter
inclusion
for
calibration
is
fission
Ultimately,
accuracy
ers
the obvious
has
and that
due 3)
to the time
of rare
in a glow a glow
potential
tube
moves
high
gas
has
Indirect
study
be taken
of the feasibility
gas
fission
coaxial could
product
with
distance the
stearates
(from
techuiquee
may
gases
themselves
decay
products
gas
from
the wire.
rare
be useful are
too
chain ,of rare
gases of rare
where
days
their
volts
gas
dc
maintained on the
Heating at room
re -
temper
-
and radia-
daughters: cognizance
through
were
in
of some
activities
themselves,
gases
yields gas
emanate gases gas
short-lived
of reasonable
collected
hundred
Rn 222).
for
through
gases rare
are
of the half-lives
and the daughter
Fractional
products
are
rates
of daughters
which
retained in studies
Trace
co”unting
performed
should
their
daugh-
in which
rare
coilected on a negatively charged wire 78, 79 Rough half-lives for the rare gases
stream:
flow
for
each
as the cathode
and the discharge
range
for
discharge:
pressure
A few
count-
calibrated
a tube
used
of the gaseous
experiments
E were
microns
“helium).
g as activities
early
daughter
amounts
the decay
activities
(in the percent
of studying
some
a moving
along
relative
where
Thus
be obtained
rare
discharge
rare
in a glow
gas
can
of gases.
or foils
and retention
of counting
requires
manipulation
hundred
air,
a glow
of rare
not a method
activities.
a few
proved useful 76, 77 .
activities
Although
ter
with
deter-
one
be separately
on wires
but it is quantitatively
technique
of rare
accurate
a direct
the uBe of these
time
on the cathode
(nitrogen,
surprisingly
The
4)
along
Deposition
the activity,
ature.
g ases
to cause
minutes.
is
for
must
solution
calibrated
While
purposes,
counter
It is often
been
involving
in a short
be deposited 5. chamber. “ Tracer
“is applied
cathode
that each
saves in the
the target
already
performed.
all
may
the discharge
a few
been
and its
determination
of measurement.
have
practically
cases
of the carrier
experiments
of samples
of rare
discharge
discharge
to support
for
required
gases
actual
f by assaying
counters
have
in most
pressure
of fissions
must
drawback
without
the temperature
of course,
a number
Deposition
amounts
factor
which
in targets sufficient
counting
sample
~rom
for
information
the measured
the number
of fiseions
achieve
tions
O°C
product
(e. g. , M099). mination
for
Po”c to
to determine
some
no useful
work.
corrected
possible
provides
in the counter
considerable counter
jacket
very
to count,
half-life
33
for
have
activities
leaving
counting
activity
rapidly) the
also
as a function been
found
studied
in heavy
of through metal
and on container walls 63 Such deposit.
stearate
is inconvenient
or where
but the immediate radiochemical
assay.
or
the rare subsequent
5) gases
Rare
have
main
g as
been
such
that
light
output
tion
denmity). 6)
which
The
have
to be
counting: satisfactory
of such
scintillants
as fission
fragments.
is dependent
feasibility
grown
studied
in this counting
retained
as
Ag I or
quantitatively
VI.
Pd12. for
the highly
energy
COLLECTION
parent
The of which
largest
collection
the author
er ences
given
The calling
attention
author
would
is aware
be included
to as many
in such
â&#x20AC;&#x201C; F.
Lawrence
Figure
nitrogen,
stainless condensates containing
F.
Momyer,
of train
balls
other
Kr
and plated samples
radiochemistry General
Ref-
with
a view
to The
as possible.
procedures
which
should
AND
Jr,
, et al.
of the
pump, -5
to 10
system
more,
used
of a trap
AIR
work
at
California
in the reparation.
refrigerated
A
in liquid
and a mechanical forepump is used to -6 mm Hg. Proceeding from Left to right
let us designate
glass
by a glass
unpublished
Liver
and label
1) a flowmeter;
of activated
Xe FROM
SEPARATION
Laboratory,
and suitable
and preceded 100 grams
10
OF
consisting
diffusion
the following: steel
gaa
description
concerning
a photograph
pressure
the separation
discussion
rare
and operations
SUBSEQUENT
arrangement
a mercury
a base
THEIR
Radiation
1 shows
pumping
separated
into the plated
one of the nine
for
techniques
1 â&#x20AC;&#x201C; REMOVAL
AND
standard
for were
a collection.
PROCEDURE
Source
plated Xe133
monograph. chosen
information
activities
PROCEDURES
with
in the last
were
useful
gas
GASES
dealing
of this
property
in vacuo.
RARE
is found
rare
was
growing
of heavy
(and not on ioniza-
activities, 135 and
RADIOCHEMICAL
THE
procedures
appreciate
even
of papers
at the beginning
following
Radioxenon
OF
that the rare 80, 81, 82 The
desirable
expended
of counting
of their
weeks,
FOR
along
have
instances
samples
in counters.
be borne in mind. For example Xe 83, 84 manner. Fission product iodine
out for
obtain
on total
to note
to be in the counting
They
only
solid
scintillants
promises
in specific
into
It ia interesting
should
counting,
was
found
usefulness
particles
scintillation
2) wool
coil;
charcoal;
34
Tl, plugs
3)
Cl, 4)
for a trap
purposes packed
to retain a trap
C z,
fine
similar
C3, and,c4,
of later with
3/16
particles
in. of
to Tl
but
three
small
-
Fig. 1 â&#x20AC;&#x201D;Separat;onsystena
used
35
in Procedures
1 and
1A.
PROCEDURE er traps trap
each
containing
similar
to the preceding
and
removal; through
the
8)
charcoal
trap
off from
the
photograph
trace
with
be directed behind
the drape), The
a vibrating
reed
of the bench.
during
thermocouple
respective
Grade-G yield
The
material.
system
is used
of samples, problem
tion
size,
has
work
The
yields
and partial
successfully
achieved
which
the largest is
100 cc STP about
the separation sample
into
of active
90%
for
is about
â&#x20AC;&#x153;pinnedâ&#x20AC;? 1.
the glass coil
feet
krypton
krypton 8 hours
the system.
and
Before on until
(probably
less
Gallon
dewars
coils.
The
the
the
than
the system,
of air
for
95~0
run all
are
of liquid
refrigerant
mm
Hg).
nitrogen
are
level
should
traps
vacuum
placed
types
not treat
a
of
which
separa-
a frame-
be described. into
a bottle
xenon.
time
required
have
gauge
con-
Average for
Bpent in bleeding
charcoal
thermocouple 10-4
The
to
various
for
of active
xenon.
and
and sieved
and to afford could
are
is Columbia
does
compressed
3 hours
traps tubing,
from
gases
seen
is the
the extremes
of rare
and 75 cc STP
of whibh
mill
gases
to represent
of operatiom
(STP)
large
char coal
in a ball
by
in the ionization
glass
admittedly
pressures with
The o. d.
to
partially
of the recorder
The
of rare below
chosen
number
100 cubic
to 350 â&#x20AC;&#x153;C and pumped is
It was
rates
sample
are
separation
chamber
and thence
of activity
of 22-mm
described
the
is amplified
the recorder
25 and 20 cm.
the
encountered. flow
been
within
taining
for
trap,
chamber
record
by this be closed
an ionization
charcoal
ground
may
that helium
and meter.
(6- 14 mesh),
obscured
nitro-
from
through
drives
traps
in liquid
not obvious
To the left
supply
about
and the procedure
often
sample
output
sample
so arranged
the ionization
a continuou6
power
charcoal
mesh
trap,
ia obtained.
are
been
for
to the line
cooled
Partially
subsequent
and the small
lengths
activated
20-50
Thus
gauge
of 41-mm
any
whose
a ~eparation
have
is
an unpacked
an outlet
and C ~ which
1 certainly
charcoal
through
electrometer
vacuum
constructed
into
current
at the right chamber
and stopcocks any
trap
T
It is
a stopcock.
through
This
between
7)
T2,
is admitted
the helium.
manometer
5)
a ZOO-CC bulb;
left.
from
charcoal;
Helium
lower
impurities
system
the atmosphere.
their
at the
is another
6)
manometer.
but connections
may
(unseen
trap
of activated
three;
a mercury
charcoal
gen to remove
flow
10 grams
1 (Continued)
been
the heated
in the manifold
on T ~ and C ~, including
be above
the
connection
from
to trap. 2.
ed to the librium
Through line
a pressure
below
pressure
gauge
the flowrneter,
o~er
C ~ is about
and reducing Sample 35 cm
36
Hg.
valve
is bled Wait
into
the sample
is cormect
T ~ and C ~ until
a few
minutes
until
equithe r -
-
PROCEDURE mal
equilibrium
boiling
is reached
of the liquid 3.
Using
establish
flow
35 cm
Hg pressure. air
Keeping until
with
10 cm Hg.
4.
all valves
from Close
to all
the charcoal
ization flow
nitrogen
is
from
Set up helium
rapid
), 6.
nitrogen, liquid
up,
slush
C2. stop 7.
* 61,
periods.
in at the above for
the pressure
rate
a few
in the bottle
removal
of the
efit at
minute
of T ~,
psi
gauge
in the traps
through
to the air.
from
C ~.
high
30 liters
Allow
pressures STP
water.
in about
5 minutes,
will
of air
Krypton
than
C ~,
the ion-
When
steady
C ~ to warm
in the
system
adsorbed
activity
will
the activity
S1OW1y (full -width
is lees
side 1-2
on C ~). be ob-
rising
rapidly
at half-maximum
1% of the peak
value
( 10-15
is halted. flow
of 750
Elute
per
flow
a couple
Corporatio~
and proceed cc/rein)
Equipment
.
37
through
to the air.
of minutes
approximately
(750
minute
and thence
in the ionization
immediately
the helium
cc STP
chamber,
appears
Research
Massachusetts
per
avoids
off more
at the helium
equilibrium
10-20°C
the activity
C2 and after
elution
Direct
National
is
the system.
nitrogen
(This
C ~ in
5â&#x20AC;&#x153;C).
If activity the
prolonged
quantitative
and thence
of the roughly
the ionization from
into
cc STP
nitrogen,
dropping
When
(-78.
1250
chamber
Set up helium
nitrogen
acetone
of
(4 cfm)
Pumping
and introduce
flow
the liquid
immerse
the elution
of
minutes.
and then
into
at about
condensation
Pump*
sample
reduce
and pres sure
of helium
in liquid
5-10
2 minutes).
minutes
will
sufficiently
Thermal
resorption
to a miximum
over
by C ~ and the stopcock
flow
in the ionization
about
of air
valving,
minute
to avoid
Ballast
the
suitable
S.TP per
one atmosphere.
C3 and C4,
remove
for
10 minutes
served
from
C2
established
too
After
C ~ and
Gas
bleed
completely
on C2,
by cessation
in air
amounts
represents
traps.
chamber,
slowly
open
This
from
is neceaaary
is about
the manometer
liquid
5.
and decreased
the bottle.
place
be evidenced
pressure
15 liters
Rotary
replenished,
in the bottle
to about
gases
pressure
large
nitrogen
minutes
on the exit
An NRC-4S
the necessary
the liquid
by steady
T ~ and C ~ of
Reduced
the pressure
rare
pump
through
in the system.
to handle
evidenced
nitrogen.
a mechanical
sample
liquid used
as
1 (Continued)
immerse
ten minutes chamber with
so that the
in liquid
C2
this
the
in dry
to remove
before
the next
Division,
C2
Remove
ice-
air
period
is
step.
sequence
Newton
is C2
Highlands
in
PROCEDURE dry
ice-acetone,
air.
Remove
The
krypton
and stop
the elution
Repeat
9.
With
Step
C4
less
no loss
than five
minutes,
10.
T2
residual
warming
nitrogen,
minutes
to conden~e
the
to the vacuum
krypton
in the
liquid
nitrogen
one pumps
tion
from
successively
pres
from
higher
ume
in the
5-10
of the system
and TZ may krypton
be
about
is
steady,
for
been Tz
the
907’.. and
cooled
in liquid
warmed
11,
Place
boiling
the krypton
by any
into
on C2
position.
at
the total
Remove
to
of air,
leaving
of krypton
pressure of krypton.
the stopcock
water,
and the
distillation
of residual Lf the vol
between
and the pres yield.
Yield
bulb
attached
and remove
from
the
38
the trap
temperature
vestiges
and pump
evolu-
and each
is at 40”C
an evacuated
and C4
until
above,
temperature,
time
the liquid
minutes
room
of the
It should
of krypton
by heating
distillation
by rotat-
pres sure
observable
beforehand,
to room
off briefly
about
of
a few
(The
nitrogen
reaches
to keep
last
by
pressure
the trap
off the
the krypton
the partial
described
system.
determination
nitrogen,
water
When
complete
measured
to get a rough
outlet
in air
4 in less
accomplished
losses.
ice-acetone,
pump
slowed
has
wishes
the process
40 “C).
seriously
about
Distill
❑peed
in the
closed,
measured
to warm
(dry
--
minutes
thus
C
step.
contains
the gas
in T2
should
from
T2 in liquid
Hg (the vapor
in the manner
down
C4
the open
to reduce
on the ther-
to one micron
the pressure
through
one
of krypton be
than ten
This
to the next
through
time
condensed
mm
the trap
temperatures
system
to T2 will
Allow
is
is 2-3
the pump
water
in the
less
of helium
down
T2 pumping
and that
slows
Hg pressure
C4
air).
of gas
warm
sure mm
beyond
use
activity take
micron.
essentially
gases
manifold
krypton
and allow
chamber.
the pressure
point
is
and every
on T ~ to a minimum
C4
evolution
and finally
once
not pump
of air
beyond
temperature)
of gas begins,
time
2-3
that
system
which nitrogen
system
until
in the removal
evolved
evolved,
ing the
in mind
water.
to C4.
than one
At this
removal
in the
stopcock
until
(should
and proceed
nitrogen.
The
112 atmosphere
be borne
pump
does
pumping
in liquid
any krypton
Elute
C3
is less
and results
Lf th”e trap
HLOWIY, pas sing
C4
. value
from
in the manifold
air.
and out to the
1O-2O”C
at that point.
discontinue
Place
and some
30 seconds
in liquid
of krypton.
with
in the ionization
1% of the peak
krypton
gauge
than five
than
nitrogen,
and replace
minutes
7 to elute
still
vacuum
require
less
C2
in 1-2
is about
is
C3 in liquid
from
appear
chamber
8.
mocouple
with
will
at half-maximum
),
chamber,
ice-acetone
activity
Full-width ionization minutes
the ionization the dry
1 (Continued)
C4
sure
should
o: be
to the system
line.
down
to base
pressure
PROCEDURE to remove
traces
in liquid
nitrogen,
12.
The
The
may
furnace
set
of peak
will
to reach
to speed
the
cooling.
cc STP
per
minute
of 1250 chamber,
be eluted
in liquid
C2
to C2 from
to about
an eventual
temperature,
to room
then
through
nitrogen
C ~ at room
and thence
C ~ in boiling
water
by heating
C ~ more
rapidly
Elute
to less
30 min.
temperature
of 350°C.
place
to the
in about
an hour. in a than
l%
activity. 13.
Set up helium
nitrogen, Warm
flow
the ionization
CZ to about
(less
flow
be reduced
the traps
helium
the ionization xenon
time
Cool
and admit
Set up helium
temperature, air.
of krypton.
1 (Continued)
than five
furnace
minutes).
pumped
Elute
off if any is present,
Xenon
losses
are
slight
gen temperature
xenon
in liquid
is
be 9570 or greater)
and distill
through
C2
in liquid
and thence
Bmall
krypton
to C4
using
either
to air.
peak
which
appears
boiling
water
or a
). C4
and the xenon
about
minute nitrogen,
any
nitrogen,
in this
only
per
in liquid
away
12 (15 to 30 min.
T2 is cooled
cc STP
C4
40 “C and throw
as in Step 14.
of 750
chamber,.
process
warmed
to 100”C,
distilled
to T2 in 10-15
as the vapor
50 microns.
pressure
Measure
to an evacuated
bulb
residual
air
minutes.
af’ liquid
nitro-
the xenon
yield
(should
removal
from
the line.
for
Comments 1. higher
For
smaller
be condensed
one
in T ~ at -195
with
krypton
but partial each
could
The
distill
fastest
-y
coil
currents
before
sate
through
T ~ in liquid balls
off
to the
dissolved
gases
by passage
Thaw are
xenon outlet
removed.
through
at the
Tl
Hg)
left
It is
carbon
of the
rack
remove
rack
the
to produce
eddy
room
tem-
in the conden-
dioxide, coil
and at -78.5
and cooled until
the C02
the xenon
Cool
above
the
times
usually
however.
occluded
from
with
of the xenon
C ~.
coil
to well
several
or by distilling
at -195*C,
is as follows:
the xenon, dioxide
originally
be considered
from
been
are
that this
mm
recovery
rapidly have
upper
39
also
an induction
the water
On another
Ascarite
from
and carbon
and” refreeze
happens (2-3
the eluti’on
may
distill
may
T ~ and C ~ separately
them
which
(It seldom
should
Use
heat
pressures
of the xenon
qutitative
from
nitrogen.
and thus
and then
attached
the trap
recovery
coil
a bulb
nitrogen.
the
partial
is higher
s=rting
air
the glass
be noted.
over
gas
fraction
and one wishes
residual
Distill
xenon
the rare
pressure
the xenon
to accomplish
the coil.
liquid
vapor
to C ~ before
to recover
into
water into
Pump
occurs
xenon
in the steel
perature’.
“C should its
of krypton
If this
convenient
glass
since
pressure
sample).
more
in which
T ~ the pos sIibilit y that a large
over
occurs
samples
from
in
occluded from
“C
the
a bath. at
or
PROCEDURE about
-150
‘“nlimh’” few
“C into
‘C
Iugher
Cron
●
obmerved
and active from the
of the
in terms
xenon,
Reparation
appears many
quite
in thio
likely
to speed
then
pas
without
onto
❑
radioactltity.
In one
dismlled
was
observed
one
elanon
that the wo
directly
run unth reactive
of 5 x 103 was
may Kr
ham never
off of C7 afrer
elutions
One
condemning
fracfiono
m the krypton.
suboequeni
at a
C ~.
and xenon
wan
at mopemane
isopemane
the dintillauon.
water
of the krypton
of their
activity
factor
-11
of xenon
Hg no liq~id
to remove
diotide
the krypton
preo n me
mm
aaed
on 11
-contamunon
vapor
a few
M usually
carbon
C ~ and no xenon
The
in only
ice-acetone
dry
Moot
2.
(- 160-C)
temperature
use
and Xe.
been
lzq-aid nimogen.
temperature
of coarse
1 (Continued)
krypton
the elimon
A lower
calculated.
could
limlt
for
It thun
be eliminated
m
experiments. 3.
The
inclusion
tion
chamber
coal
haH proved
elution
rare
to allow
of air
efficiently
rather
from
the
the
than
tid
charcoal
elu~on
in many
trapa
Kr
hams
with
elated As
the loruza -
from
the char -
an example,
can be performed
of the am
to register
on the
in series
opecies
conralmng
“peakl-..
in &e
thermal
with
chamber.
one
conductivity
obo ●rved
of prewously
the
more
Also,
in the ionization
peaks of the carriers purely
cell
operauono.
the emergence
●nough
not active
operating
conductivity
of nonra&oactive
can obo erve
❑ampleo
can observe
detection
to be a valuable
if one
gaa
of a thermal
cell
retention
nmem. 4. of tie
In a recent
system,
of 30-60
modiflcarlon
the. second
mesh
5A
Linde
wtich
small Molecular
in diameter
and
ically
50 cc STP
of each)
Eluting
the mixture
*1E
about column.
and then
raioing
follotig
r-am: ;CH
~,
long.
data Kr,
with
peak
peak
PROCEDURE
This and clad
have
though
from m
retenmm
C2
is used
for
U
hundred
milhgrams
only
of the
one
to the
cc SIP
18 mm.
targets
col~
minute
U235
1 cm (typon
at -195
“slush..), were
, full-width
“C,
the
fo-and in
at half -maxim-m
at half -rnaxim~
SEPARATION
FROM
about
mixturen
dichloride
per
60 gramo
satisfactorily
top of thm
, full-width
AND
235
very
(ethylene
with
cohmn
of methane-krypton
35 min.
PRODUCTS
the versatility
replaced
glass
performed
-36 ‘C
rime
time
to improve C3 # wao
in a coiled
been
1A – REMOVAL
procedare
in a few
Even
Sieve
He I1OW of 600
rerention
FISSION
trap,
Separanone
the temperature
eluuon
several 3rnin.
120 cm
promioes
charcoal
OF
Kr
AND
8 h.
Xe
TARGETS
of the order
of 100 mg
m weight
of 2S alummum. rare
4
gasea
is of interefir
it m the pracnce
to
PROCEDURE add carriera amount
for
both
of carrier
the co~ting
added
would
The
Buch as must
funnel
been
the top fitted
1.
fitted
with
an
at room the
with
onto
With
carriers ping
considerations 100 cc STP
be used
outlet
concerning
each
of krypton
active
a 34/45
ball
joint.
in caBe
at the
extreme
inner-tapered
gases
is
ground-
a 8eparatory
through
The
Safety
solutions
flask
the top of which
evolved
ground-glass
the separation.
diBsolver
with
into
for
for
to catch
The
fitted
the
carriers
is attached
in the flask
trap
an arm
at
to the right
targets
the
entire
as the diffusion The
C ~ at -195â&#x20AC;?C.
Tl
at the upper
and the tapered
from
is negligible.
the stopcock
to expand
other
is cooled
joints
dissolver
left
of
of the
greased
and
system.
This
of the rare
gases
alternative
is to pull
from
ice-acetone
and
open
the carrier
bulb
iB
uranium
the
in dry
be
may
fumes
back
with
water
above
more
efficient.
essary
few
3. other
cc
Close
gases --
orous
warm
Close
onto 5.
through of helium
and
of 30L70H202
cooling
the neck
pressure
to 20-30 bulb
cc
air
in
C ~ in
few
cold
some
mm
this
to reflux
Rate
of reac-
towel
contain-
most
pleasing
(See
for
be nec-
4 below).
Dilute
in an ice
flushing.
cooled
bath.
Pull
The solution
Hg of hydrogen. originally
cooled
and probably
and cool
carrier
of thewater
it may
â&#x20AC;&#x2DC;Note
water
by dr,ip-
condenser
atmospheric
solution.
It was
during
A wet
of a reflux
to allow
solution
added.
esthetically
with
to retain
if necessary.
splashing
of the flask
the
the
the flask.
approaches
to C ~ during
carrier
Start
Inclusion
is more
C ~ to a residual
slightly
boiling 4.
gases
the
drops
the solution.
of solution
onto
system.
or
the dissolver
some
of the
a few
around into
If hydrogen
to transfer
the final
with
by warming
be -appeal
and acid ice
the rest
HCL
controlled
C ~ closed,
before
through
in concentrated may
ing ice
boil
1 may
joint
is evacuated
most
The
nitrogen. 2.
tion
Air
behavior.
Ascarite.
is placed
temperature
system
liquid
18/9
containing
together.
flask 34/45
The
with
target
permissible
but
and containers
bottom
sealed.
A bulb
The
usual
later,
be provided.
an outer
the fLaBk is packed
rack.
of tracer
.,
Bhielding
round
fitting
has
by the
Bhown in Figure
of course
is a 250-ml joint,
is determined to be performed
as
of breakage left
the vagaries
be typical.
ByBtem
precauti~ns
glass
to circumvent
operation
and xenon
1A (Continued)
to avoid
should
too vig-
operation.
the
stopcock
to C ~ and open
the
the
stopcock
to C ~ and admit
carrier
bulb.
Again
pull
all
Cl. Close
the
separator
for
this
final
funnel. flush
Pull of the
the air system
41
a few onto
would
cm
C ~.
Hg of air (Provisions
be desirable).
to the for
system the use
PROCEDURE
6.
Krypton,
temperature The
final
will. be
is nearly
7. are
target,
assuming
vioasly
determined.
assay
Mo
99
calibration
for
for
the purpose
Step
air,
dry
fission
ice-acetone.
of the
experiment
88
Kr
of fis Oions
product
4.
and the
in calibrating
the number
this
little
from
an example,
to determine
factors
very
by the elution
As
nitrogen
on C
contains
necessary
solution.
at liquid 1 starting from
now
procedure
removed
analyses
on the target
are
as the sample
quantitatively
one might
and air
the previous
simpler
Radiochemical
performed
counters
hydrogen
, and one follows steps
hydrogen
xenon,
1A (Continued)
in the
to have
been
pre -
Notes 1.
The
guishable
system
(the
has
same
to within
tern in which
a portion
solution,
rest
the
finally
flushed 2.
liquid
nitrogen
gon will this
bubbled
out through
and xenon.
The
3.
heliurxi
=gon
is adsorbed and eluted
are
involving 135
Xe
by s light
be checked other
4... targets, with
the
filled
which
limited
the
would
with
may
ultimate used
for
a desiccant,
quantitative successfully
the total transfer for
syste”m
argon, and xenon
at -78.5
“C.
The
is present;
within
charcoal
has
generally
a few
ever
not very
where
Procedures
the
results
fraction,
4 and
solution
at
ar -
and in
hours
been
of
observed.
sensitive would this
5 contain
such
of wrious
inclusion
conversion
to
be greatly
point
should
examples
ahead
evolved amount
of
42
to water,
per chlorate.
of carrier to
of targets
of
packed’
followed The
volume
, and the fact
of the carriers
the dissolution
and sizes
of T ~ of a trap
of convenient
of unburned
interchange
types
of hydrogen
as magnesium
in a system
of hydrogen and a small
simplifies
the krypton
s eparationa the
of the xenon
recommend
be dissolved
gases
entire
to
the solution.
to separate
if air
sys -
prior
removal.
to 500 “C for
by the volume
the rare
is complete
been
author
Detaile,d
of iodine a syetem
CUO and heated
target
contamination
closely.
means
In building
by a trap
only
more
effective
iodine
indistin-
the argon.
Results of the experiments performed were 1135 contamination, however. Ln e~eriments affected
used
with
and oxygen
135
system
and the
been
are
with an earlier
in through
along
to purify
which
to the
solution, bubbled has
reaching
of I
obtained
off the charcoal
nitrogen used
runs
admitted
the clear
the system
meana
no evidence
those
was
C ~ with
from
In experiments
“irradiation,
from
through
temperature,
chemical
2-37’)
in calibration
of air
not be separated
case
results
of the carriers
In the absence
krypt~n
given
size
is then
that the a ystem
hydrogen
after
and activity C ~.
Such
weighing
not contains
dissolution as
well
a system. up to a few
as
has grams.
PROCEDURE
Z –THE AND
Source
The product
procedure
described
from
dissolved
2.3
roughly
ried
out IIfumelesslyi[
over
the solution
recombine Solution
is
nitrate
complete
in about
to the purification
is finally
fluehed
with
2. which carbon
and
7)
with
the charcoal from
sure about ing
one
3.
Argon
liter
per
Upon
Sofnolite
which
excess
krypton
is accom-
dissolution
is car,-
by admitting of ~ter
oxygen
are
during
result
used
is a solution
of oxygen
removal
to
solution.
is
used
of fission
of uranyl to main-
and the dia solver
hour
with
gases
around
rough
system
gases
to
attached
“sudden bursts
helium)
final
to the system
with
cop-
800 ‘C, From
to the point
maintains gases
which
.
-
compounds
at about
parallel
within
dry-
or hydrocar
of entry
one atmosphere
of evolved
2)
temperature.
return
f i~with
flow
3)
and gaseous
turnings
in
CaC12,
by reaction
nitrogen
by two identical
unidirectional
with
of hydrogen
uranium
at liquid
(mainly
is maintained
of oxygen
of hydrocarbons
clean’
an apparatus
drying mixture),
oxidation
is initially
balloon
during
of the pres
Circulation pumps
of
consist-
the pressure
ii
and cooling. of the dissolving will
ae an impurity
on the charcoal
removal
on charcoal
permitting
trap
1)
from
traces
system
heating
circulated
(an NaOH-CaO
4)
6)
inflated
completion
the charcoal
adsorbed
The
atmosphere
present
The
the vessel
complete
product
Dissolution
6 liters into
treatment:
by reaction
remaining
by periodic
helium
A brief
out methods
fission
of nitrogen
dissolution
are
any water
trap,
bf a chamber
varied
5)
adsorbed
A loosely
at one
with
gases
the dissolver.
helium.
metal.
to point
at 104”C.
A slight
the dissolver
Sofnolite,
removed
rare
of fission
uranium.
containing
and the final
during
perchlorate,
at 600 “C,
removed
of nitrogen
the recovery
“container.
back
to effect
the following
removed
magnesium
turnings
bons
leaving
receive
dioxide
ing ~th per
them
20 hours
helium
Eakins,
(1957).
below
Approximately
train
J,
train.
Gases
they
slugs
to oxides
3N — HN03.
tain flow
2216
ie for
is given
steel
respect
and wash
in approximately
I/R
of 10N IZN03 —
1).
Chadwick,
experiments.
stainless
Note
Kr85
of irradiated
uranium
with
fumes
the purification
scale
12 liters
(See
acid
AERE
involved
OF
J.
in thim paper
-kilogram
in a 70-liter
with
Evans,
amounts
to smaller
Three
G.
kilogram
PURIFICATION
USES
report
of the operations
be applicable 1.
are
Wilson,
J. “Taylor,
krypton
plished
J.
Industrial
K.
description may
– E.
EXTRACTION,
contain
all
and flushing the fission
in the oxygen
and till
in fact
43
used
constitute
for
the dis solver
product
krypton
dissolving the bulk
will
with and xenon. also
be
of the adsorbed
PROCEDURE
gaHes
(several
hundred
and the rare evacuating rectly
gases with
cc STP).
desorbed
a Toepler
to the final of the rare
gas
transfer
the gases
first
rare
gases
4.
contained
The
traps.
All
but the
second
graphic long
are
pheric
nitrogen.
pressure
train
transfers
first
finally
upon
diffuse
bands 5.
counter n,oted
the bulk
complete
at the head
in the effluent trap
to the
column.
in 2-3
more
in case
Activity
from
the column
The
carbons
krypton
pretiouely
by charcoal cent.aining uraniun
fication
mixture.
of helium
set
sample
cooled
at atmos up through
around
the first
column, gases
-
20 cm
trap
charcoals
all
chromato
The
charcoal
in about
the
trap
and
deposit
while
still
point
the
all
three
an hour
in
column
with
soon
a few
removed
water
and circulating
to remove
of the kryp-
Helium
percent from
by warming
is
of hydro
-
krypton
the krypton-
the evolved and then
any hydrogen
the pressure
subsequent
nitrogen.
volume
hydrocarbons,
char -
background
most
and unseparated
are
is
as activity
traps
adsorbed.
in liquid
contain
by uranium
As
a GM
activity
to the last
charcoal
point
still
cooled
with
Until
and approaches
at this
These
when
is monitored charcoal.
from
and all the xenon
temperature
complete
the
in judgment).
is stopped
may â&#x20AC;&#x153;at this
in boiling
from
through
at 800 â&#x20AC;&#x153;C to decompose
is considered
about
the column
line
of an error
elution
traps
at room
charcoal
is the
the remaining
is directed
undecomposed
charcoals
uranium
Ieawing
to pass
chromatography.
turnings
of
convenient.
of five
chromatographic
dewar
aliquots
as
trap
of the dewar
to the
exit
appears
.
The
the
the flow
is changed
off the charcoal
6.
phoric
gas
hours
ton removed pumped
near
(a precaution the flow
smaller
to
of the column.
in the gas
placed
hour
convenient
in a column
all
di-
the run and then
to the first
per
and
or if the total
singly
second
to saturate
liters
of the
The
ice-chlorobenzene
lowering
of the argon
be most
before
The
the line
be transferred
of a train
of charcoal
from water
pump,
be purified
consists
is introduced of 3.5
may
bulbs.
then
is transferred
removal
gases
to a vacuum
a dry
in boiling
it may
nitrogen.
Gradual
Radioactivity
is noted
steady
traps.
suitably
may
is removed
the Toepler
of storage
10 grams
C with
and a flow
of charcoal
large,
in liquid
Helium
desorbed
apparatus
to be separated
trap
charcoal
is very
and outgassed
to -50â&#x20AC;?
the
with
bulbs
It contains
and is cooled
in liquid
The
to a series
in these
cooled
charcoal
apparatus
purification
are
gases
pump.
fraction
heated
column.
of rare
coal
final
The
by warming
purification
volume
2 (Continued)
gases
over
over
pyro -
resulting.
in the system
reaches
Puria
state. 7.
Krypton
is transferred
to suitable
44
etorage
bulbs
with
a Toepler
pump,
,
PROCEDURE
or by adsorption nitrogen
on charcoal
2 (Continued)
contained
in the
Btorage
bulbs
and cooled
to liquid
temperature.
Notes 1. The
dissolution
dissolution
U +4.5 k
The
HN03
in -
02
11. 7M — HN03
U02(N03)2
the pre Bence
3/2
of uranium
~ U02(N03)2
proceeds
+ 1.57
of oxygen,
in nitric
+ H20,
has
according
NO +0.84
however,
acid
NOZ +0.0005 for
are
85
in detail. equation:
NZO +0.043 the reaction
of nitrogen
ofides
studied
to the following
the equation
so that
been
NZ +2.25 is
H20.
U + 2 HN03
not present
in the
productB. 2.
Xenon
at 100”C after
could
if desired.
xenon
of course In this
activities
have
be recovered
particular largely
There is a report 133 of Xe from uranium.
amounts remote very
control similar.
in fact
The
used.
argon
As
xenon present
in the
in the Kr85 with
stainless
As
purification)
steel
Cleanup gauge
and is
solution nitric
of acid
through vapor
10-20
a trap and N02.
solution at -509C
ed the
same
smaller gram
and oxygen packed
when
amounts
of Xe
with
glaBs
rare
step
consists
system. rings
removal
all
the Bteps
are
removed
essentially
and heated
to 550-600
cold
glass
pyrex
measurements
uranium “Effluent
and cooled
of xenon
and the helium
gases
final
krypton
of a “C .
with
was
stream
was
carried
gases
were
to -80° again was
a McLeod
effected
B.
out with passed
C to remove
paBsed
A
surface.
no further pressure decrease occur 133 (of the order of 50 millicuries),
of irradiated
to adsorb pattern
than
pressure
complete
(after
is
with
The
product
is
the
gases
column.
this chips
apparatus
the rare
other
calcium
and
than argon,
in the procedure
for
of multi-curie
purification
a charcoal
of
the procedure
of the fission
on an adjacent
periodic
amounts
Complete
step
levels
o~ shielding
adsorbed
containing
from
impurities
in a smaller
with h,eliurn,
strongly
high
recovery
problems
column
iB die solved with
of radioactivity,
and most
apparatus
containing
considered
obtain
argon
is deposited by taking
from
charcoal
the final
The
crucible
is followed
on the
trace 7
of calcium
To
trap
sample.
getter.
more
uranium
working
the early
levels
than by elution some
a calcium
‘Imirrori!
rather
contains
the
and preliminary
so much
by pumping
at -90 “C,
fraction
dissolving is
the chromatographic
to avoid
describing 86 Aside
by the high
same
xenon
is removed
the trap
the
introduced
procedure
decayed
radioactivity.
from
water
by sweeping
through
a charcoal
t e xenon. Subsequent purification of the xenon followi except that O. 03 cc STP of inactive xenon carrier was
a dd’e d.
45
+
3 –RAPID
PROCEDURE
PRODUCT
Source
– G.
D.
O’Kelley,
Phys.
This study The
procedure
and the
was
operation
technique
for
REMOVAL
Kr
used
removal
H.
N. 102,
Rev.
are
FROM
OF
Lazar,
223-227
to obtain
FISSION
U FOIL and E. (1956)
samples
briefly
described
of krypton
from
Eichler,
of the
below
the target
Rb 89
15-min.
as given may
for
prove
for
this
purpose.
useful
in other
context~. The eter
target
Pt disk.
Al foil
of aluminum
passage
bottle
the recoil
chamber
1. neutrons
Target for
2.
3.
from
target
The
cap
double-walled
hypodermic containing
and air
coafial trap
outer
packed
evacuated charged Due
annulus with
cell. strip
“few percent
glass
the
needle.
3 min.
Air
. 1s 2.6
end of
the pile
via
to decay
chamber
is flushed
The
in dry 89
down
The
foil
the center
gases
exits
are
is
collected
J.
Hoagland
Radio chemical
with
a
tube
of the
through
the
through
and thence
into
a an
on a negatively 89 and Rb counted.
removed
FISSION
chamber,
and a
PRODUCT
U METAL
and N.
Sugarman,
Studies:
National
Nuclear
Book
McGraw-Hill,
2,
OF
3 min.
passed
recoils penetrate to the recoil 138 of Cs is found on the foil.
4 – RECOVERY
tube
out for
is punctured
ice-acetone is
with
a pneumatic
chamber
effluent
of Kr
and irradiated
min.)
allowed
in the recoil
Xe FROM — E.
A rubber
at the opposite
xenon
PROCEDURE
Source
Kr
recoil
and cooled daughter
for
by activity
with
This
but permit
chamber.
line
in a pile
89
from 89
than
the krypton
wooi 89
some
chamber
chamber.
fragments
recoil
etit
placed
rapidly
sealing
Rb
of Al foil
the
the
of Kr
of the needle.
The
to straggling
are
half-life
shorter-lived
hype,
into
recoil
recoil
Xe fission
and seal
chamber
(The
is removed
rubber
and the
on a 1. 6-cm-diam-
the target.
and recoil
isotopes
stop
fragments
to cover
3 minutes.
The
and krypton
should
fission
used
deposited
end of a vacuum-tight
the uranium
absorber
cap is
(O. 3 mg/cm2)
at one
between
of the krypton
serum
film
It is mounted
a 3. 12 mg/cm2 amount
is a uranium
The
”Energy
Fission
Series, New
Paper
Products,
Div.
York
147:
(1
IV, 51)
Vol.
pp.
9,
1035.
!? This iodine
procedure
and xenon
dent fission
yield
fiesion
effects
rapid
products. 135 of Xe .
dissolution It was
46
of the target
designed
for
and separation
studies
of
of the indepen-
PROCEDURE 1. attached
The
uranium
is evacuated one half
amount
from
The
ual ofide
for
or
if present
-85”C,
The
an activated
to this The
point
gases solution,
at -85”c.
The
- 195”C.
h
desorbed
gases
evacuated thin-window
after
ity may
min.
some
10 min.
resid-
amount
of
dissolution
on the trap
indicated solution.
now
at -195
“C.
300
cc of helium
The
procedure
for
second
are
trap
to 250”C
taken
trap at
and the pump
to an
by filling
bulb.
the target
sweeping
charcoal
by a Toepler
counting
the storage into
on the charcoal
is heated
transferred
of xenon
the helium
at
the end of an irradiation.
are
is
growing
trap
about
trap
at -85”C,
off.
all the xenon)
135
after
,a cold traps
1, below).
charcoal
from
cold
charcoal
with
Note
of the krypton
the first
of Xe
any
during
through two
swept
(See
closed
Aliquots
be transferred
is
of the krypton
and counting
or NaHS03
to about
is dissolved
and an activated
within
by repeating
experiments
tion,
Air
a small
of a small
solution,
containers
amount
irradiation
Early
and
(containing
be determined
admitted
not onidized
in succession
the solution
procedure
gas -tight The
and the flask
containing
by the addition
passed
is immediately
bulb.
HC1
an NaHS03
of 3-4
remainder
this
is then
the metal
ion was
at -85 ‘C,
a period
storage
5.
trap
the xenon
After
iodide
are
is complete
f’lask
All
flask,
is to be performed.
concentration.
can be completed
dissolver 4.
that
in low
charcoal
in concentrated
be dis solved
found
NaOH
Hg over
separation and helium
carrier.
liberated
dissolution
at 10 cm
may
It was
a cone.
When
!Iholdbackli
originally
3.
in the dissolver
the
apparatus
is dissolved
carbide
ERQ03.
in which
pressure.
target
of 1-
is placed
line
the entire
atmosphere
2.
cone.
target
to the vacuum
4 (Continued)
solution
at a suitable
from known
I
135
later
may time
an aliquot of the xenon fraction so obtained. 135 no I reached the first cold trap, NaOH soluThus
directly
the helium
sweep
to the storage
containing
bulb,
the xenon
and aliquots
for
activ-
counting
taken.
Note 1.
The
double
ed in the article. For
sweeping
horizontal glass helium
joint. may
The
with
atis
-etided
The
closed
helium
of the
dissolver end is
the flask
sidearm
solution
be introduced.
flask used may
qpnnecting
then
rests
A small
used for
be
solution
rotated
it to the
on a sintered bulb
47
in this
between
procedure of the target
through system glass two
is illustrat-
180” through
disk
and
about
the
a tapered
through
stopcocks
storage.
below
which the
4 (Continued)
PROCEDURE
sintered
glass
Efficiency
disk
is used
of xenon
removal
PROCEDURE Xe
Source
This
procedure
of Xe135.
The
enclosed
target
carrier,
bubbling
dissolve’
the
gen
is bubbled rough
pellets,
bubbling
traps
are
ant still Xe
on the
obtained
Kr
and
in a well -ty-pe for
repeating
PROCEDURE
about
of xenon
tilling
flask,
by flushing running
uranium
A.
(1953).
yield
U02(N03)2
solution
through
after
activities
. 6H20
of KI as holdback evacuated.
acid
H2
admitted
is boiled
a reflux
temperature
condenser
in succession.
and sealed
on the first is
chamber.
Later
activity
trap,
counted
hydro-
containing
the end of irradiation.
activity
is
to
while
water
a trap
pressure
are
xenon
50 mg
temperature,
Ayres
OF
from
LONG
and 1. B.
Charcoal off with
and
Kr
by placing
samples into
the
-LIVED
FISSION
cool-
but no
the
of xenon
growing
Nuclear
Book
McGraw-Hill,
3,
used
uranium
sample
and the flask
connected
apparatus the
metal,
rate
with
Fission
Series, New
of the
char -
may
solution
be by
results
product
of reaction
48
The
uranium
being
IV,
(1951),
Vol. pp.
9,
1763.
of various reproducible
xenon
to the purification C02.
Products,
Div.
York
GASES
311:
efficiencies
and gave fission
Paper
The
Energy
in studies
containing
Johns,
Studies:
National
was
in 92~o H3P04,
The
5-microns
of the xenon
– J.
the entire
242
sweep.
procedure
removal
The
or
sulfuric
at dry-ice
30 min.
ionization
1:1
pass
traps
Radiochemical
This
.31,
and the apparatus
and hot
6 – SEPARATION
Source
,
PRODUCT
of the independent
containing
gases
The
determination
the hydrogen
Chem.
studies
rapidly.
than Xe
9570.
TARGETS
of U03
to dry-ice
until
second.
for
system,
charcoal
to less
J.
sweeping.
to be about
FISSION
mg
solution
cooled
is continued
found
for
capsules.
in a flask
Effluent
and two
was
OF
200-300
and contents
a trap
of helium
- 6H20
Can.
designed
were
the
through.
in place.
trap
Yaffe,
to the vacuum
evacuated
activity
coal
used
through
drying,
REMOVAL
aluminum
capsule
for
also
is placed
attached
started
H2
targets
sweep
OR UOZ(N03)2
and L.
was
in thin-walled
The
NaOH
U03
Brown
out aliquots
by the helium
5 – RAPLD
FROM
– F.
to measure
train.
controlled
to 2-3~0
is placed Air
is then
methods
is
in a dis removed
dissolved
by warming
by or
.
PROCEDURE
cooling
the flask
the acid. enter
Xenon,
which
train.
is condensed gases
then
The
sample which
being
with
chamber
remaining After
to provide
GM
rest
PROCEDURE
from
COLLECTION
ON
Source
OF
THE
–F.
F.
The has
overall
proved
wires
or foils The
radon
thorium
evacuated,
and hot
solution,
through
is complete 4 cold
traps
the pump keeping
it immersed
in liquid
trap
are
finally
cooled
and a glow This
discharge
technique
procedures.
has
Usually,
10-5
into
ITS
solution
Hg.
are
The
distilled
a tip on the glow tube a few
discussed
small
are
amounts
49
is then
minutes earlier
percent.
of rare
gas
proto,ns
on
to produce
the EyEtem
fluosilicate
bubbled.
catalyst
through
ice/acetone,
solution
closed are
to the
the others discharge closed
off from
trap
The tube
off,
to collect
off and the
shut
last .
sodium
and then
After
are traps
It
gases,
nuclides.
flask,
in dry
and warming
run for
a few
in liquid, nitrogen.
mm
discharge
been
tl@n
340-Mev
gases
hydroxide
nitrogen
The
counting
Chemistry,
ammonium
cooled
in the traps
distilled
nitrogen.
AND
retention
of rare
with
Evolved
to 10. “-
down
of the xenon
Hyde,
in the dissolver
a trap
pumped
condenmed
and
HC 1 containing
traps
chamber
TUBE
and Nuclear
is no more
, irradiated
through
3 succe~sive
K.
of gas .
of the
A DISCHARGE
characteristics
the thorium. passed
Th TARGETS
collection
is placed
and gases
in liquid
counting
the
concentrated
aliquot
Rn FROM
into
with KOH,
volume
to a counting
The
and E.
solution
by reaction
of the volume
OF
amounts
the uran-
(1955),
and sodium
cooled
cathode.
target
the
handled
connected
of Inorganic
the dissolver
of this
warmed,
metal
by spallation,
from
H20,
small
After
the sample.
procedure for
of decay
in to dissolve
hydroti,de passed
of this
however,
in studies
isotopes
dropped
yield
useful,
swept
and
containing
Momyer
274-95
KOH.
of
NaHS03
the Hz to
xenon
sealed.
CATHODE
Journal 1,
is
a saturated
over
an easily
knowledge
of the system
7 – REMOVAL
is
bulb
counter
be calculated
and of the
active
point
and tellurium
o~dizes
is removed
the C02
to an evacuated
finger-type
may
The
behind
iodine
through
hot CUO
flask.
at the boiling
product
the gases over
fast
in a audiometer
in if ’necessary
is withdrawn an Al
counted
Bubbling
collected
C02.
is very
fission
Passage
any xenon
be swept
into
some
in a subsequent
are
is dissolved,
may
and
I and Te.
the audiometer air
hydrogen,
removes
of other
Dissolution
required.
the purification
solution
ium
as
6 (Continued)
by
contents which
is
the tip radon
on the
in this
monograph
under
of condensed
impurities
pro-
,
PROCEDURE
tide
a few
hundred
the case,
one
the necea~ary may
for
in later
pressure
add some
prea~ure
cathode use
microns
may
7 (Continued)
gas
to support
much as air,
in the discharge
be frozen
back
into
the last
the disc~r.ge.
nitrogen
If this
or helium
tube.
Any
trap
at liquid
radon
nitrogen
of radon
produced
is not
to achieve
not deposited
on the
temperature
experiments.
Notes 1, ment
Stoner
of gold
mercury
while
2,
and Hyde
with
nitrogen
being
Matt+ur
was
‘The 3.
-195
The
“C
ments
with
water
be largely briefly
activity
product
removed
in air
Distillation
from
was
gas
ceased
fission
vapor
pressures
sures
of the tracer
in the
cold
tal data.
It seems
a result
of processes
under system
which
with trace
at -195°C
worth
are
It was
gases
also
a ~ -y
to drop
rapidly
activity
into
produced The
removed
from
radon
pro-
gases
involved
attention the rare
e=mple,
must
could
certainly
alone
be involved), might
Well
exceed
the gases
until
over
the partial
pres
further
is,
not be held
of The
solids.
so that
the
90~0
Retention Speculation experimen-
that the retention (that
“C.
thus.
experiments.
without
could
at -195
be removed
of the pure
to the fact
all
trap
at
experi-
activity
and continued
30 see).
pointless
gases
~-y
containing
in the above
seems
in traps
in the radon
another
meter
(about
not due to condensation
for
isotopes
gases
interfering
in the, radon
of rare
of rare
the trap
at - 195°C
gases
possible.
the target.
in the
observed
and their
by warming
substances
xenon,
in
procedure.
and the xenon
amounta
survey
involving
other
from
x~non
used
dissolved
omitted. of trace
calling
by bombard-
was
a similar
of traps
with
amounts
is thus
system
products
product
mechanism
deficient
series
gold
the radon
uEing
the fission
of the rare
traps
as to the exact
condensation
radon
monitored
neutron
upon.
rare
and distilling
in the trap
the rare
retention
The
to remove
protons
same
was
be commented
that fission
fashion.
in a closed the
scrubbing
observed
should
studied 100-Mev
through
NaOH
iaotope~
in similar
by induction
with
by pumping
cedure.
heated
of KI
dissolved
solution
studied
ions
and Hyde77
by bombardment KI
76
adsorption
is not on or
circumstances
up in a portion
of a
-
PROCEDURE
8 â&#x20AC;&#x201C; DETERMINATION BY
Source
â&#x20AC;&#x201C; C.
R,
THE
Dillard,
Paper
68:
National
R.
short-lived
over
rare
a porous
New
gases
graphite
a baffle
.syatem,
ia connected aluminum
tube
center
of the tube
ia maintained
tera
of gaaeoua
linear
of gaa
gaa
wire
into
a daughter
volta
a number
of appreciable
51
Turkevich,
Products: 9,
Book
2,
the half-lives
interesting
may
be bubbled. spray
A fine
copper
to effect
From tube
lengths
half-life
The to
down
apparatua
while
data
the
Thus
and determining
may
ia
maintaining
be calculated.
the half-life
the
of the daugh -
experimental
may
piece,
wire
entire
neutrons
vessel
carry-over,
collection
The
with
of
technique.
polystyrene
to prevent
of equal
on each
accuracy.
Vol.
in a small
the ayatem.
-LIVES
624.
the tube.
irradiated
the aluminum
activity
Fission
nitrogen
through
through
through
and A.
IV,
this
diameter.
at -1000
a olution
of daughter
with
inner
passing
of nitrogen
rate
amounta
rare
1 -in.
and the
the collector
relative
fair
flow
flow
cutting
lived
activities
in a reactor
a constant
of
using
contained which
vessel
pp.
HALF
(H)
to determine
through
a 10-ft
placed
through
is
The Div.
(195 1),
performed
GAS
Finston,
Studies: Series,
York
nitrate
disk
H.
experiments
were
of uranyl
ACTIVE TECHNIQUE
Adams,
Energy
of the earlier
A solution
M.
WIRE
Radiochemical Nuclear
McGraw-Hill,
A number
OF
CHARGED
by
the
of a short-
be determined
with
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