Optimization of bremsstrahlung MeV X-ray generation from laser-plasma interaction

A. Aghedo, D.R. Rusby, N. Lemos, H. Chen, A. Kemp, J. Bude, F. Albert, C. Scarlett and A.J. Mackinnon

Generation of MeV bremsstrahlung radiation from high-intensity laser plasma interactions is capable of radiographing high-areal density object at high temporal and spatial resolutions [1]. The optimization of efficiency and flux of such a source is of key interest to these applications. An analytical model for bremsstrahlung x-rays from laser-plasma interaction was developed by Compant La Fontaine [2], which shows the key parameters as the laser energy and intensity. We have expanded on the existing analytical model by incorporating laser focal spots and pulse shapes to generate a more realistic electron source. The extended model has also been applied to existing laser facilities (such as NIF-ARC, Titan and Omega-EP) to determine the optimum laser and target parameters. Results from this model have been compared to previous numerical models and recent experimental data taken at Omega-EP.

[1] Courtois et al “High-resolution multi-MeV x-ray radiography using relativistic laser-solid interaction” Physics of Plasmas 18, 023101 (2011); doi.org/10.1063/1.3551738

[2] Compant La Fontaine “Bremsstrahlung spectrum and photon dose from short-pulse high intensity laser interaction on various metal targets” Phys. Plasmas 26, 113109 (2019); doi.org/10.1063/1.5118361