Speeding up electrons like a roller-coaster ride

A unique superconducting technology that speeds electrons.

Susan Bettenhausen (left), William Jansma (right) and Matthew Kasa (center) work on the helical superconducting undulator being readied for installation at Argonne’s Advanced Photon Source. (Image by Argonne National Laboratory / Richard Fenner.)
Susan Bettenhausen (left), William Jansma (right) and Matthew Kasa (center) work on the helical superconducting undulator being readied for installation at Argonne’s Advanced Photon Source. (Image by Argonne National Laboratory / Richard Fenner.)

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have developed a new X-ray device that speeds up the electrons like a roller coaster.

This new Insertion Device (ID) also known as Helical Superconducting Undulator (HSCU) uses a unique superconducting technology and offers three primary advantages over other types of IDs for producing high-brightness X-rays:

  • Generates a stronger magnetic field than other IDs
  • Allows researchers to select a single energy from the X-ray beam without using any X-ray optics
  • Produces an X-ray beam with circular polarization

Scientists suggest that the device with fascinating benefits allows them to collect data faster and more cleanly than with other, similar technology. It does not require an additional optical device to perform experiments.

Matthew Kasa and Susan Bettenhausen of the APS Accelerator Division Magnetic Devices Group put the finishing touches on installation of the Helical Superconducting Undulator in Sector 7 of the APS storage ring. (Image by Argonne National Laboratory / Richard Fenner.)
Matthew Kasa and Susan Bettenhausen of the APS Accelerator Division Magnetic Devices Group put the finishing touches on installation of the Helical Superconducting Undulator in Sector 7 of the APS storage ring. (Image by Argonne National Laboratory / Richard Fenner.)

A helical superconducting undulator is an extremely difficult gadget to coordinate into a working electron stockpiling ring, for example, the one at the APS, on the grounds that it presents solid restrictions on the treatment of the electron shaft in the capacity ring. It may cause disturbances in-ring activities and, henceforth, in the conveyance of X-beams to holding up analysts.

The brilliant mechanical and attractive outline of the HSCU loop geometry created by APS designers and physicists makes it nondisruptive to the relentless task of the APS stockpiling ring. Scientists just know the HSCU is there a direct result of the X-beam bars it conveys.

Efim Gluskin, an Argonne Distinguished Fellow and previous APS division executive who has driven the undulator program at the APS from its beginning, compared the movement of the electron group in the HSCU to the circling movement of a curling thrill ride like the X Flight ride at the Six Flags Great America carnival close Chicago. As electrons corkscrew through the gadget’s attractive field, they produce the circularly enraptured radiation.

Argonne’s Helical Superconducting Undulator team includes Efim Gluskin, Yury Ivanyushenkov, Yuko Shiroyanagi, Joel Fuerst, Ibrahim Kesgin, Matthew Kasa, Quentin Hasse and Susan Bettenhausen (left to right). (Image by Argonne National Laboratory / Richard Fenner.)
Argonne’s Helical Superconducting Undulator team includes Efim Gluskin, Yury Ivanyushenkov, Yuko Shiroyanagi, Joel Fuerst, Ibrahim Kesgin, Matthew Kasa, Quentin Hasse and Susan Bettenhausen (left to right). (Image by Argonne National Laboratory / Richard Fenner.)

But in order to force the spiral motions of electrons, an extraordinary magnet must be worked with a solid spiraling attractive field. That objective was refined by wrapping superconducting wires around a corkscrew-molded segment of iron. The final product is a 1.1-meter-long superconducting electromagnet with numerous winding molded, rotating north-south attractive shafts; when the HSCU is invigorated, these attractive posts send the electrons on their winding way.

The HSCU provides analysts with a more intense X-ray beam that takes into consideration quicker information obtaining than traditional undulators, at timescales of a billionth of a moment. Like customary undulators, the new sort of undulator can empower examine on a scope of complex marvels, including the advancing elements of a complex liquid stream and the magnetism of metals.

The device quickly transfer a monochromatic X-ray beam directly from the undulator to the sample being studied without the help of a monochromator. Moreover, it offers more coherent beam since any optic will have small imperfections that can introduce unwanted distortions into the X-ray beam.

On the top of that advantage, the ability to produce circularly polarized radiation is important, since circular light is sensitive to properties of a material such as magnetism and molecular chirality — or handedness — that linear or unpolarized light cannot see.

Jonathan Lang, director of the X-ray Science division at the APS said, “They can bring this beam directly from the undulator and do a standard imaging experiment like you would have an X-ray taken in a doctor’s office or a dental facility. But you can do it very fast here.”

“The single wavelength provided by the new undulator will permit experimenters to examine how materials evolve at even faster timescales than were possible before. By looking at the X-rays and how they scatter and shimmer, we can tell how molecules are moving around in the material and on what timescales they are moving around.”

According to scientists, the device will become a common tool for future light sources and free electron lasers because they outperform existing permanent magnet undulators in the delivery of bright X-ray beams for a wide energy range. It will also be used to perform phase contrast imaging to highlight certain aspects of the phenomena under study, such as diesel fuel that is composed of various light elements called hydrocarbons.