Bremsstrahlung cannon design for shock ignition relevant regime

P. Koester, F. Baffigi, G. Cristoforetti, L. Labate, L. A. Gizzi, S. Baton, M. Koenig, A. Colaïtis, D. Batani, A. Casner, D. Raffestin, A. Tentori, J. Trela, C. Rousseaux, G. Boutoux, S. Brygoo, L. Jacquet, C. Reverdin, E. Le Bel, L. Le-Deroff, W. Theobald, and K. Shigemori

Rev. Sci. Instrum. 92, 013501 (2021)

Abstract

We report on the optimization of a BremsStrahlung Cannon (BSC) design for the investigation of laser-driven fast electron populations in a shock ignition relevant experimental campaign at the Laser Megajoule-PETawatt Aquitaine Laser facility. In this regime with laser intensities of 10¹⁵ W/cm²–10¹⁶ W/cm², fast electrons with energies ≤100 keV are expected to be generated through Stimulated Raman Scattering (SRS) and Two Plasmon Decay (TPD) instabilities. The main purpose of the BSC in our experiment is to identify the contribution to x-ray emission from bremsstrahlung of fast electrons originating from SRS and TPD, with expected temperatures of 40 keV and 95 keV, respectively. Data analysis and reconstruction of the distributions of x-ray photons incident on the BSC are described.