Nanosecond time-resolved Raman spectroscopy of molecular solids under laser-driven shock compression

Time‐resolved Raman spectroscopy of polystyrene under laser driven shock compression

“…The details of the 1D simulation are discussed elsewhere and omitted here for the sake of brevity. By using time evolution of Raman peak intensity ratios, the shock wave velocity inside the polystyrene sample is estimated by the following equation: U s = r . t , where U s is the shock wave velocity, r is the rate of change of Raman intensity ratio and t is the thickness of the Polystyrene.…”

“…For example, Hare and Dlott studied the dynamics of poly‐methyl methacrylate (PMMA) micro gauge undergoing photo‐thermal laser ablation by picosecond coherent Raman spectroscopy and indicated the generation of monomer due to thermal decomposition. Zheng et al had reported the time‐resolved Raman spectra of anthracene under laser‐shock loading and measured the shock velocity from the intensity ratio of the shocked region. However, the shock induced chemical and physical changes in many polymers are still not well understood.…”

In Situ Raman Spectroscopic Studies of Liquid Carbon Tetrachloride (CCl4) Under Static and Laser-Driven Shock Compression

“…From the simulation results, we learn that the shock takes a time of almost 104 ns to traverse the whole sample. Shock velocity in CCl 4 was estimated from the temporal evolution of the Raman intensity ratio of shocked peak intensity to original peak intensity using the equation given by Zhang et al., 29 Us = r · t , in which Us is the shock velocity, r is the rate of change of Raman intensity ratio obtained from the slope of the plot of intensity ratio against the delay time shown in Fig. 8, and t is the thickness of the CCl 4 sample in µm.…”

In situ Raman spectroscopic studies of polyvinyl toluene under laser‐driven shock compression and comparison with hydrostatic experiments

“…At delay times of 24, 31, 38 and 66 ns, the Raman intensity ratio belonging to the shocked volume are 0.053, 0.256, 0.446 and 0.852, respectively. By using the following equation: U s = r . t , where U s is the shock velocity, r is the intensity ratio and t is the thickness of the PVT sheet, the calculated shock wave velocity is 3.6±0.46 km/s.…”

“…Vibrational spectroscopy is an effective tool to investigate the real‐time effects of shock compression‐induced chemical and structural changes in the material . Some interesting and sophisticated shock experiments are performed during last couples of decades . However, the shock‐induced changes inside various polymers are still not well understood.…”