用于激光等离子体X射线诊断的谱仪

X-ray diagnosis spectroscopy of laser-produced plasma

为了诊断波长为0．5～0．8nm的激光等离子体X射线，研制了一种新型的高空间和光谱分辨率的晶体谱仪。采用2个不同分光计材料、不同形状且相互垂直分布的通道可以同时获得谱线的空间和光谱分辨率。利用成像板接收光谱信号，其有效接收面积为30mm×80mm。讨论晶体基本参数和给出了谱仪设计参数。在中国工程物理研究院激光聚变研究中心的20J激光器装置进行实验，两个方向的成像板同时获取得到了Al激光等离子体X射线光谱，其中水平通道的PET平面晶体获取的空间分辨率为1．73～6．88mm，而垂直通道的Mica球面弯晶得到的光谱分辨率达到1000～1500。实验结果表明该谱仪适合于激光等离子体X射线的光谱学研究。

A new crystal spectrometer with high spatial and spectral resolution was designed to measure very low emissive X-ray spectra of laser-produced plasma in the 0.5 nm to 0.8 nm range. Twin channels collocated perpendicularly with two different crystal materials and forms were utilized for simultaneous measurement of spectral and spatial resolution. The imaging plate was employed to obtain high spatial resolution with effective area of 30 mm × 80 mm. The basic parameters of crystals were analyzed and the design parameters of the spectrometer are presented herein. The first experiment was carried out at the 20 J energy laser facility of Research Center of Laser Fusion, CAEP. X-ray spectra were obtained from At laserproduced plasmas with a spectral resolution of 1 000 to 1 500 for the spherically bent mica crystal spectrometer and spatial resolutions of 1.73 mm to 6.88 mm for the flat PET crystal in the same condition. It is suggested that the device be used in high-density plasma diagnostics of a single laser shot.