7th International Conference on Matter and Radiation at Extremes (ICMRE2024)

 Laser driven inertial confinement fusion (ICF) is an important experimental platform for high energy density physics research under extreme conditions. Excessively expected hydrodynamic instability is a key factor affecting fusion ignition. The evolution process of instability growth in real materials is extremely fast, the time scale is large, and the modulus change is very small. And there is currently no effective diagnostic method for in-depth research. This talk introduces a high time resolution diagnostic system for two-dimensional velocity field, which is called compressed ultrafast photography (CUP)-velocity interfere system for any reflector (VISAR).It produces the interference pattern carrying the information of shock wave velocity field by interference technology, then using the new compressed ultrafast detective module to record compressed interference patterns. In order to reconstruct dynamic interference patterns, double-channel sampling technology will be used to reduce the loss rate of compression sampling, and the depth mining of sparse feature will be taking to optimize the precision of reconstruction. Based on the 10kJ laser facility, the dynamic verification experiment was carried out to diagnostic the dynamic evolution process of the shock wave velocity field. Line-VISAR and CUP-VISAR were used to measure the velocity history in the same region, and the accuracy of velocity diagnosis was compared and analyzed. Each time-varying interference image is reconstructed, and the extracted x-t section image is consistent with the line-VISAR results. The relative error is less than 6%,
 

Optical diagnosis,two-dimensional velocity field of shock wave,compressed ultrafast photography