Peering into the Atomic Level The Advanced Photon Source at Argonne Lab

Peering into the Atomic Level

The Advanced Photon Source at Argonne Lab

BY LARRY ATSEFF

One of the most impressive and impactful labs at Argonne is the Advanced Photon Source (APS). The APS is, in effect, a giant X-ray microscope in the form of a huge, complex ring, large enough to encircle each of Chicago’s Major League Baseball stadiums.

According to Steve Davey, technical operations specialist at the APS, it is one of the most productive X-ray light-source facilities in the world, providing highbrightness X-rays to 5,000 researchers annually in the fields of materials science, chemistry, condensed-matter physics, life and environmental sciences and applied research.

NEAR LIGHT SPEED ELECTRONS FLOW FROM THE ACCELERATOR TO A CHAMBER WHERE THE MICROSCOPIC X-RAY IS TAKEN.

“X-rays are produced by electrons that are accelerated to high energies, moving at nearly the speed of light as they pass through arrays of large, powerful magnets," Davey said. "X-rays are emitted as the magnets steer the electrons around a ring measuring two-thirds of a mile in circumference. Throughout the ring, X-rays beams are delivered to enclosures, where researchers set up various instruments and experiments to investigate the structure and chemistry of a wide variety of matter.”

“The APS X-rays are extremely bright and penetrating, allowing them to peer through dense materials, ranging from metallic engine-blades to full-sized mummies,” said Jonathan Almer, physicist and group leader in the X-ray science division of the APS. “X-rays lie on the part of the electromagnetic spectrum where their wavelengths match corresponding features of atoms, molecules and cells, just as the longer wavelengths of visible light match the sizes of the smallest things the human eye can see. This allows us to measure atomic-scale properties with high precision. We can also do this very fast—such as seeing shock-waves—since the APS X-rays are about one billion times brighter than X-rays produced in a dentist’s office."

JÖRG MASER AND ROBERT WINARSKI, OF ARGONNE'S CENTER FOR NANOSCALE MATERIALS, X-RAY MICROSCOPY GROUP, AT THE HARD X-RAY NANOPROBE BEAMLINE ON ADVANCED PHOTON SOURCE (APS)

In sum, the APS has helped scientists go far beyond a basic knowledge of materials and processes to actual controlled testing at the most basic levels of matter.

For example, the APS has been used to better understand energy storage, manufacturing of materials, information technology/nanotechnology (even smaller matter), research of pharmaceuticals, advances in bio-medicine, oil and gas, transportation, agriculture, the environment—virtually everything that affects our lives every day. As a result, we now have improved processes for oil extraction from shale. Today, our batteries last longer, recover faster and can be more effectively recycled. Our vehicles are more fuel-efficient, materials that go into our infrastructure have been made stronger, and our electronics, from computers to smart-phones to data storage, are more powerful and efficient. Pharmaceutical breakthroughs have led to medicines that stop the progressions of deadly diseases. We also have a better understanding of our solar system and the earth itself through APS studies of meteorites and space dust, which have been compared to the rocks and minerals around us.

USING A NEW X-RAY IMAGING TECHNIQUE, SCIENTISTS WERE ABLE TO GET A 3-DIMENSIONAL RECONSTRUCTION OF THE ARGONNE NATIONAL LABORATORY LOGO WITH A NANOMETER RESOLUTION FROM THE SURFACE LAYER OF A SAMPLE. FIGURE A: SHOWS AN IMAGE PRODUCED WITH A SCANNING ELECTRON MICROSCOPE. FIGURE B: SHOWS THE ARGONNE LOGO. FIGURE C: SHOWS THE IMAGE AS 2-D COHERENT SURFACE SCATTERING IMAGING DATA.

Scientists have even used the APS to uncover historical and archaeological secrets by studying the composition of an ancient Egyptian mummy and the arms of SUE, the Tyrannosaurus Rex specimen at The Field Museum of Chicago.

Even with all that success, Argonne is not standing still. This past July, it was awarded a $815 million grant to upgrade the APS, which will keep Argonne in the world forefront for Advanced Photon Source technology for years to come.

The APS staff we talked to are excited by the upgrade. They have a right to be, because it will enable observations of individual atoms moving and interacting, in real-time, looking at real samples, for everything from biological organisms to complex engineering systems. This will be due to the fact that brightness of the X-rays will be increased 100 to 1,000 times, depending on the techniques they use.

Consequently, staff believe the upgrade will lead to advances such as:

• Revolutionary systems to convert sunlight into energy and new ways to store that energy;

• New drugs to treat a myriad of diseases;

• A better understanding of the way the brain processes and stores information with neurons;

• Understanding how pollutants move through soil;

• A better understanding of the structure in Earth’s inner core; and

• Cleaner, more efficient bio-fuels.

The upgrade for such a complex facility will take several years. In the meantime, the APS will continue to play host to thousands of researchers a year, from all over the world and all disciplines, to take advantage of the power and versatility of the system. Two Nobel prizes have been awarded based on research done largely at the APS.

APS staff will continue to work closely with visitors as they conduct their tests and experiments. ■