Physicists at the SLAC National Accelerator Laboratory have achieved a groundbreaking feat by creating electron beams with peak power levels equivalent to a million nuclear reactors combined. These ultra-short bursts of energy have the potential to revolutionize the study of matter, model astrophysical phenomena, and conduct experiments in quantum physics.
Recently published in Physical Review Letters, the research showcases a novel method for compressing electron beams, resulting in pulses with a power of one petawatt and a duration of just one quadrillionth of a second. Despite this incredibly short timeframe, the beams carry a current of 100 kiloamperes.
The key to this remarkable achievement lies in the technique of alternating acceleration and compression. By utilizing standard magnetic “chicane” technology to guide the electrons and condense them into ultra-short bunches, the researchers were able to maximize beam density. To overcome the limitations of conventional methods, the SLAC team introduced a unique approach: before compression, the electron beam interacted with a specialized magnet and a laser pulse, creating a distinct energy gradient within the bunch, which facilitated more efficient compression.
By iterating this process multiple times, the scientists were able to reduce the bunch length to a mere 0.3 micrometers, setting a new record. This advancement not only paves the way for more powerful X-ray lasers but also holds promise for generating megampere electron beams capable of producing virtual particles from vacuum, a phenomenon predicted by quantum theory but never observed experimentally.
The team’s next objective is to enhance the method by replacing the laser with a plasma cell, which is expected to further shorten the bunch length and bring them closer to creating megampere electron bunches.