Advances in High Repetition Rate Laser-Driven Particle Sources Based on Ambient-Temperature Liquid Jet Targets
Griffin Glenn, Stanford University
Laser-driven sources of ions and neutrons have attracted interest for a variety of applications in fields from fundamental physics to medicine and materials science. These sources exhibit several desirable characteristics, such as MeV energies, high peak brightness, favorable emittance, and ultra-high acceleration gradients. However, the low repetition rates previously available using conventional laser and target technologies have presented a significant challenge in realizing these applications. Our group has developed ambient-temperature liquid jet targets that address many of the limitations of conventional target systems. This target platform produces planar liquid sheets with thicknesses ranging from hundreds of nanometers to several microns and has demonstrated robustness against high laser intensities as well as target thicknesses and orientations that are tunable in situ.1
Here I will present high repetition rate ion and neutron sources produced using this target that make key advances towards maturity for applications. In an experiment at Rutherford Appleton Laboratory, we performed real-time closed-loop optimization of the laser-driven ion beam and accelerated protons with energies up to 6 MeV at a repetition rate of 5 Hz. In a subsequent pair of experiments at Colorado State University, we demonstrated 0.5 Hz acceleration of MeV deuterons2 and the first high repetition rate laser-generated neutron beam in the pitcher-catcher geometry, with peak neutron energies up to 7 MeV. I will conclude with a brief discussion of upcoming experiments in which we will pre-expand this target to produce target density profiles which we anticipate will provide access to peak energies beyond those accessible using the conventional TNSA mechanism.
This work was supported by the U.S. DOE Office of Science, Fusion Energy Sciences under FWP 100182. G. D. G. acknowledges support from the DOE NNSA SSGF program under DE-NA0003960.
References:
1F. Treffert and G. D. Glenn et al., Phys. Plasmas 29, 123105 (2022)
2F. Treffert et al., Appl. Phys. Lett. 121, 074104 (2022)