Towards Integration of Raman Thermometry and Two-Stage Light Gas Gun Shock Propagation

Capturing accurate temperature data during dynamic experiments remains an ongoing challenge in the shock-physics community but is critical for developing equation of state models during shock compression. Raman spectroscopy is a temperature sensitive technique applicable to dynamic shock experiments. Here, we investigate the application of single-shot Raman spectroscopy as a diagnostic tool for measuring temperature at high pressures (> 40 GPa) using a two-stage light gas gun (TSLGG). A TSLGG simulates extreme conditions by generating high-velocity impacts that create a high-pressure shock wave through a material. By synchronizing a nanosecond Raman laser pulse with the shock event, which lasts <500 ns, we can obtain vibrational spectra that reflect the immediate structure, phase, and temperature during dynamic compression. A challenge of employing Raman spectroscopy for the TSLGG is ensuring that the laser pulse arrives during the shockwave to provide an accurate measurement. Here we demonstrate precise control of laser timing with respect to the projectile impact within 20 ns using gas-gun facility triggers and laser operation.