In recent years, laser-driven particle acceleration has attracted significant attention as a compact alternative to conventional radiofrequency accelerators that are used in high-energy physics experiments and medical facilities. Laser-driven acceleration is based on the interaction of intense laser pulses with plasmas, which are ionized gases. When a high-power laser pulse interacts with a plasma, it can generate strong electric and magnetic fields that can accelerate electrons and ions to very high energies.
However, one of the challenges in laser-driven acceleration is to maintain the quality of the accelerated particles. When a single laser pulse is used to accelerate particles, the acceleration process can be unstable, leading to variations in the energy and trajectories of the accelerated particles. This can limit the applications of laser-driven acceleration in practical settings.
To overcome these challenges, researchers at Osaka University, led by Professor Yasuhiko Sentoku, have explored a new approach using multiple laser beamlets. By splitting a single laser pulse into multiple beamlets and then recombining them in a specific way, the researchers were able to achieve more stable and controlled acceleration of electrons and ions.
In their experiments, the researchers used a high-power laser system called the "10 PW Laser Facility" at the Institute of Laser Engineering (ILE), Osaka University. The laser system can deliver ultra-intense laser pulses with a peak power of 10 petawatts (PW), which is equivalent to the total electrical power consumption of the entire United States.
By using multiple laser beamlets, the researchers observed improved acceleration of both electrons and ions compared to the case of a single laser pulse. The accelerated electrons reached energies of several GeV, while the accelerated ions reached energies of several MeV. The quality of the accelerated particles, in terms of their energy spread and angular divergence, was significantly better using multiple laser beamlets.
The improvement in particle acceleration performance was attributed to the more stable and controlled interaction between the multiple laser beamlets and the plasma. The use of multiple beamlets allowed for better control of the laser intensity and phase distribution, which resulted in more efficient acceleration and improved beam quality.
The research team believes that the use of multiple laser beamlets can pave the way for the development of next-generation laser-driven particle accelerators that are compact, efficient, and capable of producing high-quality particle beams. Such accelerators could have a wide range of applications, including fundamental research in high-energy physics, compact radiation sources for medical and industrial purposes, and advanced imaging techniques such as X-ray microscopy and tomography.
