160 / 2026-03-31 22:32:19

Development of the Experimental Platform for Laser Plasma Interaction on the Shenguang laser Facility

Laser Plasma Interaction,stimulated scattering process,Optical Thomson scattering

激光与粒子束聚变、磁驱动聚变 > 激光聚变物理

This report systematically presents the experimental research platform for Laser plasma interaction in laser fusion. Aiming at instabilities such as stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) induced by laser–plasma interaction, the research team has developed multiple scattered-light diagnostic systems on the Shenguang facility, including configurations based on off-axis parabolic mirrors, fiber-optic sampling, and diffusive scattering plates. These systems enable multi-dimensional measurements of scattered light in terms of energy, spectrum, temporal waveform, spatial distribution, and polarization. To address the calibration requirements of the diagnostic systems, polarization-sensitive calibration methods using scattering-plate targets and multi-axis manipulators have been established, significantly improving measurement accuracy. Furthermore, the combination of scattered-light diagnostics with thermal and super-thermal coherent Thomson scattering (TS) allows for the simultaneous diagnosis of SBS and the associated ion acoustic waves. Experimental and simulation results indicate that SBS predominantly occurs in the plasma near the hohlraum wall and the laser entrance hole, with a small frequency shift dominating at early times, while the plasma in the mid-region contributes a larger frequency shift. This integrated diagnostic approach provides essential experimental tools for understanding laser–plasma instability mechanisms and supporting ignition research in laser fusion.