甲10~(11)W,100ps的高功率激光以不同的偏振形式(P或S偏振)聚焦照射到铝靶表面.用X光晶体谱仪拍摄到铝的LPX谱线.激光等离子体的电子温度随入射角的变化,说明了在10~5W/cm~2功率密度下,存在着共振吸收机制.LPX光谱强度计算表明,在我们的实验条件下,固体铝靶的K_α线大部分起源于快热电子.

Using 0.1 TW, 100ps pulse-width high-power laser to irradiate the surface of plane aluminium targets with different polarizations (P-polarization or S-polarization), the LPX spectral line of aluminium ions was photographed by a X-ray crystal spectrometer. The relation between electron temperature of laser plasma and the incident angles of the laser beam was obtained. It shows that there is resonant absorption in the plasma when the laser power density is in the order of 1015W/cm2. The Ka spectral line emitted by the aluminium target originates mainly from fast electrons in our experimental conditions.