A team of physicists at the SLAC National Accelerator Laboratory in Menlo Park, California, has made a significant advancement by generating the highest-current and highest-peak-power electron beams ever produced. This groundbreaking research has been published in the prestigious journal Physical Review Letters.
For many years, scientists have been exploring innovative applications for high-powered laser light, ranging from splitting atoms to simulating conditions found inside distant planets. In their latest study, the research team has enhanced the power of electron beams, enabling them to exhibit capabilities similar to those of high-powered lasers. The driving concept behind these more powerful beams was straightforward; however, the challenge lay in the execution.
The essence of the research focused on packing as much charge as possible into the shortest time frame. The team successfully generated a current of 100 kiloamps for an incredibly brief duration of just one quadrillionth of a second. This research involved directing high-energy electron beams through an accelerator, where powerful magnets propel the electrons to extreme speeds. The electrons travel on radio waves inside a vacuum, akin to race cars navigating an oval track.
During the experiment, the electron beams were accelerated to speeds reaching approximately 99% of the speed of light. However, when the electrons approached a turn on the track, they needed to swerve, which caused a reduction in their speed. To optimize the turn, the researchers adjusted the path of the electrons to be straighter than usual. They achieved this by sending a string of electrons, measuring a millimeter in length, around the accelerator’s track.
In this configuration, the electrons leading the group traversed a less-steep section of the radio wave, allowing them to exit the turn with less energy—a phenomenon referred to as a chirp. The researchers then employed magnets to orchestrate a sequence of turns, causing the electrons to swerve left, then right, and left again before returning to their original path. This process effectively manipulated the energy levels of the electrons.
Due to the way the magnets interacted with the electrons, those with lower energy levels were deflected more than their higher-energy counterparts. As a result, the lower-energy electrons had to take a slightly longer route, allowing the higher-energy electrons to catch up, thereby compressing the electron string. The team integrated an additional magnet to facilitate the exchange of energy for light, intensifying the chirp effect.
During their experiments, the researchers repeatedly sent the strings of electrons around the track, each time enhancing the beam's power while simultaneously shortening its duration. At the peak of their research, the pulse measured an astonishing 0.3 micrometers in length. This unprecedented achievement opens up exciting possibilities for future research.
The research team believes that their innovative technique could pave the way for new work in various fields, including chemical processes, the production of novel types of plasma, or even offering deeper insights into the nature of empty space. With such advancements in electron beam technology, the future holds great promise for scientific exploration and technological innovation.
