MEASURING OPACITY OF SHOCK GENERATED ARGON PLASMAS

Plasmas are generated by passage of a strong planar shock wave through gas. Initial experiments in argon have produced plasmas with 2 eV temperature, 0.004-0.04 g/cm3 density, and coupling parameter GAMMA approximately 0.3-0.7. Plasmas having GAMMA > 1 are attainable with greater initial gas pressure. The opacity of the plasma is measured versus wavelength by recording the risetime of emitted light. Initial measurements are in visible light. Preliminary results are compared with calculations using the HOPE code.