The world’s cutting-edge particle accelerators are pushing the extremes in high-brightness beams and ultrashort pulses to explore matter in new ways.
To optimize their performance – and to prepare for next-generation facilities that will push these extremes further – scientists have devised a new tool that can measure how bright these beams are, even for pulses that last only femtoseconds (quadrillionths of a second) or attoseconds (quintillionths of a second). Comparing 1 attosecond to 1 second is like comparing 1 second to 31.7 billion years.
This tool can also measure beam sizes to within a few tens of nanometers (billionths of a meter) – without disrupting experiments that rely on these beams.
The new tool, dubbed a “charge density monitor,” could also provide more precise measures of fundamental physics in high-energy and high-field beam experiments, and help guide R&D efforts that seek to shrink the size and cost of particle collider and accelerator facilities while ramping up their capabilities.
The research using this proposed diagnostic could also impact disciplines ranging from plasma science to atomic physics, and could lead to new applications and reveal new physics.
At the U.S. Department of Energy’s Berkeley Lab Laser Accelerator (BELLA) Center, researchers hope to test this tool by measuring particle properties in the aftermath of an intense laser beam drilling through a jet of gas. In doing so, they hope to learn about the electron beam pulse emerging from this interaction.
“BELLA provides an ideal test bed for evaluating the potential of the beam-measuring method at a state-of-the-art advanced accelerator, since we aim at producing the brightest possible ultrashort bursts of electrons with our compact accelerator technology,” said Wim Leemans, director of the BELLA Center and the Accelerator Technology & Applied Physics Division at Lawrence Berkeley National Laboratory (Berkeley Lab).