The 6th International Conference on Matter and Radiation at Extremes (ICMRE2023)

212 / 2023-04-15 21:15:55

Optical Thomson scattering system for wire array Z pinch experiment

z-pinch,Optical Thomson scattering

Radiation and Hydrodynamics > Radiation and hydrodynamics-poster

Wire array Z-pinches are highly effective for generating strong pulsed X-rays and widely utilized in material science, high-energy density physics, and laboratory astrophysics under extreme conditions. But, the implosion quality of wire array Z-pinches is limited by the ablation stream and trailing mass.

To investigate the evolution of plasma dynamic behavior of plasma during the implosion process, we developed a Thomson scattering system on the Qin-1 generator that measures the electron temperature, ion temperature and plasma velocity simultaneously. This system uses a frequency-doubled Nd-YAG laser (3J, 10ns, 532nm) that focuses the plasma through an f=1m lens to create a 500μm diameter spot. Scattered light is collected at 90° and 112.5° to minimize the scattering volume and estimate electron density. Ion acoustic wave (IAW) information is recorded using a spectrometer with a gated ICCD camera. Plasma parameters are obtained by comparing the theoretical scattering spectrum.

We used this system to diagnose the ablation stream of a two-wire load. The preliminary diagnosis shows that the axial characteristics of the ablation flow plasma are not uniform, with lower density ablation streams having higher electron temperatures and faster velocities. In the future, we hope to improve the diagnostic system and achieve axial resolution scattering diagnostics using a transverse load configuration to directly measure the axial distribution of plasma parameters.