レーザー光の衝撃波プラズマによる散乱スペクトル

(Thomson散乱とCo-operative散乱) II

抄録

This report describes the observation of “Thomson scattering” and “co-operative scattering” of a Q-switched ruby laser light by shock wave plasma. The spectral distribution of the scattered light was measured at an angle of 90° and 45° with reference to the direction of the laser light. The Q-switched ruby laser light with the peak power of the order of 1 MW was injected against the position behind the shock front of the reflected shock wave (the Mach number _??_17) which was produced at the initial pressure of 0.4mmHg in argon. In the case of the 90°-scattering, assuming a plasma parameter α=0.85, the theoretical curve accords very well with the measured spectral distribution of the scattered light. The electron temperature and the electron density were determined to be 2.3×10⁴°K and 1.4×10¹⁶ cm^-3, respectively. For 45°-scattering, the spectral distri-bution of the scattered light showed a central peak and a satellite. The wavelength shift of the satellite peak was 27Å. In this case α=1.57, n_e=1.6×10¹⁶cm^-3, and T_e=2.6×10⁴°K were estimated. These values are in good agreement with the results of 90°-scattering.