High-power laser-matter interactions have been shown to be versatile sources of secondary radiation, including high-energy, high-flux particle beams. Laser-driven particle beams are typically characterized by peak particle energies up to tens of MeV, small divergence angles, and extremely high peak fluxes due to their ps-scale pulse duration. These properties are favorable for a wide variety of applications, ranging from radiography to cancer therapy and material damage studies. To fully realize these applications, it will be necessary to produce laser-driven particle beams at high repetition rates (HRR, ≥1 Hz). High-power laser sources capable of operation at HRR have recently become available, but developing targets that are compatible with HRR operation remains difficult. To address this challenge, we have developed an ambient temperature, continuously-refreshing liquid jet target based on tungsten microfluidic nozzles. Here, we describe the critical features of the liquid jet target and its successful operation as a source of laser-driven ion beams with laser intensities above 1021 W/cm2 and repetition rates up to 5 Hz. We additionally discuss progress towards key promises of operation at HRR, including machine learning-based online optimization of the ion acceleration process and the demonstration of a high average flux directed neutron source.
Authors: G. D. Glenn1,2, C. B. Curry1,D. P. DePonte1, R. Hollinger1, G. Jain1,4,S. Popa5, J. J. Rocca3, B. Sullivan3. D. Irsescu5, S. Wang3, G.J. Williams6, S. Zahedpour3,S. H. Glenzer1,M. Gauthier1
1SLAC National Accelerator Laboratory, USA
2Department of Applied Physics, Stanford University, USA
3Electrical and Computer Engineering Department, Colorado State University, USA
4Department of Mechanical Engineering, Stanford University
5Extreme Light Infrastructure (ELI-NP); Bucharest, Romania
6Lawrence Livermore National Laboratory, USA