Publications Details

Burst-Mode Coherent Anti-Stokes Raman Scattering N2 Thermometry in the Sandia Free-Piston Shock Tube

Kearney, S.P.; Daniel, Kyle; Wagner, Justin W.; Lynch, Kyle P.; Downing, Charley R.; Lauriola, Daniel K.; Leicht, Jason; Meyer, Terry; Slipchenko, Mikhail N.

Coherent anti-Stokes Raman scattering of the N2 molecule is performed at rates up to 100 kHz for thermometry in the Sandia free-piston, high-temperature shock-tube facility (HST) for reflected-shock conditions in excess of T = 4000 K at pressures up to P = 10 atm. A pulse-burst laser architecture delivers picosecond-duration pulses to provide both the CARS pump and probe photons, and to pump a solid-state optical parametric generator (OPG)/optical parametric amplifier (OPA) source, which provides frequency tunable Stokes pulses with a bandwidth of 100-120 cm-1 . Single-laser-shot and averaged CARS spectra obtained in both the incident (P = 1.1 atm, T = 2090 K) and reflected (P ~ 8-10.5 atm, T > 4000 K) shock regions of HST are presented. The results indicate that burst-mode CARS is capable of resolving impulsive, high-temperature events in HST.