Researchers developed and tested an ultrafast sample replenishment system for an X-ray laser oscillator.
September 8, 2026
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The Science
Scientists are working on a new concept for developing the brightest artificial X-ray source in the world, called an X-ray laser oscillator. X-ray free-electron lasers (XFEL) are the current strongest artificial source of X-rays. These machines produce pulses of X-rays that take ultrafast snapshots of atoms and molecules. An X-ray laser oscillator would use a XFEL to pump energy into a system, similar to the way researchers use conventional optical lasers. Once the laser excites a sample of material, the sample would radiate fully coherent and amplified X-ray pulses with a very narrow linewidth. (Coherent X-ray pulses are when waves of X-ray light are synchronized. Amplified pulses would be stronger than the original pulse.) Researchers have developed the first practical sample delivery system for an X-ray laser oscillator. Using an ultrafast rotating copper disk target, they successfully tested the delivery system at the Linac Coherent Light Source XFEL, a DOE Office of Science User Facility.
The Impact
An X-ray laser oscillator would provide users with an intense, fully coherent series of X-ray pulses. These pulses would have unprecedented spectral brightness and wavelength stability. Such capabilities could lead to breakthroughs in many disciplines, such as X-ray quantum optics or nuclear spectroscopy. In addition, scientists could use the X-ray laser oscillator concept in practical applications. These could include the next generation of industrial measurement tools for high-value processes. For example, the semiconductor industry could use it for measurement within their production lines. But this technology requires a very specific system to deliver samples. A private company sponsored by the Department of Energy’s SBIR/STTR program developed the first sample delivery system for this technology.
Summary
To make the X-ray light oscillation approach successful, researchers must able to replenish material at repetition rates of tens of megahertz. This is a critical and highly challenging requirement for sustained operation. The private company RadiaBeam Technologies developed a prototype sample delivery system. It optimized an in-house test stand that used an ultrafast rotating copper disk target. The copper disk achieved stable and reproducible rotation speeds of up to 30,000 RPM. The team later installed and commissioned the system on one of the beamlines at the Linac Coherent Light Source (LCLS).
The initial results were very promising. Single- and dual-pulse testing demonstrated amplified spontaneous emission, seeded amplification in the copper sample, and a clear, dramatic brightness enhancement of the seed pulse. The sample delivery system achieved stable high-speed operation and spatial separation of incoming XFEL pulses on the sample at a pulse repetition frequency of 14 MHz. Encouraged by these results, the project team is developing the next iteration of the system. It will enable practical deployment in a long-pulse-train X-ray light oscillator configuration at LCLS and other DOE Office of Science User Facilities.
Contact
Ronald Agustsson
RadiaBeam Technologies
agustsson@radiabeam.com
Alex Murokh
RadiaBeam Technologies
murokh@radiabeam.com
Funding
Funding for this development was provided by the Department of Energy SBIR/STTR program. The research used the Linac Coherent Light Source, a DOE Office of Science User Facility at SLAC National Accelerator Laboratory.
Publications
N. Welke, N. Majernik, R. Ash, A. Moro, R. Agustsson, P. Manwani, K. Li, A. Sakdinawat, A. Aquila, A. Benediktovitch, A. Halavanau, J. Rosenzweig, U. Bergmann, C. Pellegrini; Development of spinning-disk solid sample delivery system for high-repetition rate x-ray free electron laser experiments. Rev. Sci. Instrum. 1 October 2023; 94 (10): 103005.