A first-of-its-kind instrument developed by Arizona State University that will enable researchers to see deeper into matter and living things in greater detail has formally been launched.
The “compact X-ray light source” (CXLS) is a device that produces a high-flux hard X-ray beam with short enough wavelengths to resolve the atomic structure of complex molecules.
Its output is also pulsed at extremely brief intervals of a few hundred femtoseconds, well below a millionth of a second, making it short enough to directly observe atomic movements.
With the ASU device, a university location can now access cutting-edge X-ray science due to its incredibly small, basement-sized facility for ultra-short X-rays.
With the help of ASU's portable X-ray light source, scientists will be better able to comprehend the motions and arrangements of atoms in three dimensions, which will help them better understand how proteins work and advance drug discovery by allowing them to observe how a drug interacts with its molecular targets.
There are three major parts to the new ASU CXLS facility:
• A small, portable particle accelerator that can generate steady electron beams with energies as high as 30 million electron volts (30 MeV).
• A potent infrared laser that combines with the electron beam to create ultrafast hard X-ray pulses that have a maximum photon energy of 20 keV.
• Research chambers for scientific experiments and a tunable excitation laser for analyzing X-ray interactions with a range of research targets.
The CXLS instrument was powered up to release about 4 keV photon energy in order to produce the first X-rays. The photoinjector of the light source performs the initial phase. There, copper is exposed to 1,000 UV laser pulses per second, unleashing a cloud of electrons into vacuum with each pulse, which are then accelerated by a powerful electric field.
After that, a linear accelerator accelerates the electron bunches almost to the speed of light as they pass through a succession of magnets that direct and concentrate the beam into an interaction chamber.
The concluding step involves firing an infrared laser almost directly into the path of the approaching electrons. In a mechanism known as inverse Compton scattering, which is crucial to the small facility size, this results in the emission of potent X-rays. The electrons are guided by powerful magnetic fields into a receptacle for capture.
The downstream sample, such as proteins or other molecules, is exposed to the emitted X-rays in order to engage with it. (For the first X-ray demonstration, this step was omitted).
A YAG scintillator screen was used to conduct the experiment and prove its success. Scientists observed and tracked the beam movements and used data analysis to demonstrate that X-rays were being produced.