糖心视频

An international collaboration has developed a new diagnostic technique for measuring ultra-short particle beams at STFC's Central Laser Facility. This collaboration is led by the University of Michigan and Queen's University Belfast. The research addresses a key challenge in developing compact alternatives to kilometer-long particle accelerators.

Current X-ray free-electron lasers (XFELs), which produce laser-like X-rays for imaging at the viral scale, require facilities stretching for kilometers. These installations demand substantial resources and space that many institutions cannot accommodate.

Laser-wakefield acceleration technology offers the potential to create similar capabilities in devices small enough to fit on a laboratory bench. This approach works by focusing an intense, ultra-short laser pulse into plasma, matter where electrons and ions are separated.

The laser displaces electrons from ions, creating an electric field that causes electrons to oscillate in wave patterns behind the laser pulse, much like a surfer being pushed by waves. These waves can accelerate particles to high energies over shorter distances than conventional accelerators.

Overcoming measurement difficulties

Measuring the resulting particle beams has proven challenging due to their brief duration, lasting less time than it takes light to cross the width of a human hair. Conventional measurement techniques are inadequate for these timescales. The STFC team's solution involves using laser light to deflect particles by small amounts.

By measuring these deflections and analyzing the laser field oscillations, researchers can determine both the position and energy of individual electrons simultaneously. This dual measurement capability addresses a fundamental requirement for understanding and controlling these ultra-short particle beams.

Expanding scientific access

Professor Rajeev Pattathil, Head of Novel Accelerators at STFC Central Laser Facility, explains the significance: "Laser-driven plasma accelerators are maturing to a level where advanced light sources such as XFELs are being designed based on this technology. One of the prerequisites for this is to understand the temporal characteristics and energy of the accelerated electron bunches. Simultaneous measurement of this is important.

"By using the CLF's Gemini laser system, the collaboration has come up with a diagnostic technique that enables this measurement. This is a major step towards future light sources based on laser-driven accelerators."

The diagnostic method represents a significant step toward making X-ray sources more accessible to universities and research institutions that cannot accommodate large-scale accelerator facilities. Such compact devices could enable new research in structural biology, materials science, and medical imaging.

The research demonstrates STFC's continued commitment to developing advanced scientific instrumentation and supporting the U.K.'s position in accelerator science and technology. By enabling more institutions to access X-ray capabilities, this development could reduce the infrastructure barriers that currently limit research opportunities in these fields. This advancement contributes to ongoing efforts to make high-energy physics research and advanced imaging applications more widely available to the scientific community.