ARTICLE IN PRESS
Nuclear Instruments and Methods in Physics Research A 510 (2003) 150–157
Porous CsI multiwire dielectric detectors$ M.P. Lorikyan* Yerevan Physics Institute, 2 Brothers Alikhanian Str., 375036 Yerevan, Armenia
Abstract The multiwire porous dielectric detectors developed earlier worked stable in combination with a pulsed voltage supply, which limited their application. In this work a new type of multiwire porous dielectric detector has been developed and investigated. Such detectors operate at a constant voltage supply and thus in a permanent mode. These detectors are shown to exhibit a good time stability and a highly efficient detection of both heavily ionizing particles and soft X-rays and have standard deviation of a spatial resolution of better than s ¼ 718 mm: r 2003 Elsevier B.V. All rights reserved. PACS: 29.40.Gx; 29.40.Wk; 78.55.Mb Keywords: Porous multiwire detectors
1. Introduction In 1979 a group of researchers of the Yerevan Physics Institute observed the phenomenon of drift and multiplication of electrons (EDM) in porous dielectrics (PD) under the influence of an external electric field [1–5], which allowed them to create a new class of radiation detectors—porous detectors (PD). In these detectors as a working material, porous dielectrics KCl, CsI and so on are used and they work on the basis of the abovementioned phenomenon. The EDM in PD in an external electric field has been demonstrated as controllable by the electric field and provides a very high yield s of secondary electrons per incident heavily or minimum ionizing particles. $ The work is supported by the International Science and Technology Center *Tel.: +374-2-26315; fax: +374-2-224633. E-mail address: lorikyan@star.yerphi.am (M.P. Lorikyan).
[1–9]. When the porous emitter is traversed by minimum-ionizing particles, the secondary emission gain factor s is 250 [6]. In the case of aparticles the gain factor is several thousands [7– 12]. Later the secondary electron emission in an external electric field has also been investigated [13,14]. Afterwards, the same group of researchers developed and studied multiwire and microstrip porous detectors [12,15]. In earlier works, it was shown that the time and spatial resolution of such detectors are less than 60 ps and 250 mm: The rise time and width of pulse are p1 ns and E2 ns; respectively [15,16]. These detectors are operated in a vacuum of p10 2 Torr and can have a little quantity of material on the particles’ path. Qualitatively, the microscopic mechanism of the highly effective EDM in porous dielectric media under the presence of an external electric field can be represented in the following manner. In the pore walls, primary particles stimulate electrons of
0168-9002/03/$ - see front matter r 2003 Elsevier B.V. All rights reserved. doi:10.1016/S0168-9002(03)01692-9