Liu Yun won the Faraday Cup Award for his breakthrough laser comb

One example is the laser comb developed by the U.S. Department of Energy's Oak Ridge National Laboratory. This advanced technique, developed by laser scientist Yun Liu, allows physicists to measure particle beams in superconducting linac in real time without affecting operation. The measurements capture key information about changes in the beam particle distribution. The development and use of this technology solidifies ORNL's leadership in beam instrumentation and has led to advances in high-power proton accelerators.

"There is a coherent set of activities within the division, and we position ourselves to be able to execute the next generation of high-power machines," said Fulvia Pilat, director of ORNL's Research Accelerator Division. "This breakthrough lays the foundation for achieving the goal.

The Faraday Cup award is the most prestigious award in the particle accelerator instrumentation community and the first of its kind to be awarded to a laboratory. The International Conference on Beam Instrumentation sponsors the award in recognition of outstanding leaps in accelerator science in devices with operational capabilities. In the 31 years since its inception, the prize has been awarded only about half as often.

ORNL has such an influential beam instrumentation program because it involves the research and development of novel beam instrumentation.

"We are in a league of our own when it comes to laser-based beam diagnostics," said Sarah Cousineau, head of ORNL's Accelerator Science and Technology division. "For me, this award validates our research program. It also recognizes Yun's extraordinary leadership in developing novel beam diagnostics specifically tailored for superconducting linacs, the future of high-power proton accelerators."

The scientists used neutrons from the ORNL Spallation neutron source to understand how materials behave at the atomic scale under different conditions. Their research has created pathways to advance clean energy technologies, plastic upcycling, artificial intelligence, and therapeutics. Every year, thousands of scientists around the globe compete for beam time on SNS, the world's strongest source of pulsed neutrons.

However, producing neutrons requires a high-energy, high-powered beam of protons. ORNL's superconducting linac uses negatively charged hydrogen ions to produce high-energy, high-power protons. The front end of the ORNL linear accelerator, or linAC, fires pulses of hydrogen ions at 90 percent of the speed of light into a metal tube about 4 inches in diameter and 300 yards long.

Particles naturally want to fly away from an ion pulse or beam the size of a dime. But this flight away or beam loss means radiation can end up where it shouldn't be. It also weakens the ion pulse, resulting in fewer neutrons later in the process. For scientists, beam loss means less beam time. With these factors in mind, regular beamline studies ensure safety, identify required maintenance, and maximize the user's beam availability.

Carding beam

Thanks to Liu's laser comb, physicists conducting these beam-line studies have one less constraint. The comb solves the long-term problem of measuring the change of light beam with time; These measurements were once only possible with individual measurements. Instead, Liu's laser acts as a camera, taking a roll of photos with a single click of the shutter. Each tooth of the comb or laser pulse captures how the distribution of particles in the beam changes over a trillionth of a second. Using Liu's laser comb, physicists can not only select parts of the beam pulse for measurement, but also study changes and reveal patterns in a single measurement without interrupting the accelerator's operation.

"Yun's technique allows us to measure length, which is difficult because the beam travels almost at the speed of light," said Sasha Aleksandrov, group leader of the Beam Instrument group in the SNS Research Accelerator Department. "Yun found a solution to overcome this limitation. It will not only allow us to improve the performance of existing accelerators, but also to design more powerful machines."

In September, Liu will give a keynote speech on laser combs at this year's International Beam Instrumentation Conference in Saskatoon, Canada, where he will also receive the Faraday Award.

"I am very honored and humbled by this award. We have been working on beam diagnostics for more than a decade. I never dreamed that one day we would receive such recognition, "Liu said. "This is a great encouragement not only to me but also to many of my colleagues. We have a lot of experts in different fields on the team who have contributed to the success of the project."

Mr. Liu received his Bachelor's degree in Mechanical Engineering from the University of Science and Technology of China in Hefei, China in 1986. He received his PhD in electrical engineering from Shizuoka University in Hamamatsu, Japan in 1994. He did postdoctoral work at Shizuoka University, graduating from University in 1994, and worked as a research fellow at the Advanced Institute of Telecommunication Research in Kyoto, Japan, from 1996 to 2001. Liu is a senior researcher at ORNL's Neutron Science Council. He has authored more than 100 publications and holds four U.S. patents and three Japanese patents. Liu received the 2013 R&D 100 Award for creating a method for extracting high-quality laser beams from wide-area laser arrays for a variety of laser applications.

SNS is a DOE Office of Science user facility.

UT-Battelle manages ORNL for the U.S. Department of Energy's Office of Science, the nation's largest supporter of basic research in the physical sciences. The Office of Science is working to solve some of the most pressing challenges of our time.

Source: Laser Network