罗斯滤片法测量激光打靶X射线辐射通量

利用一套罗斯滤片系统测量激光轰击固体金属Ti平面靶产生的X射线辐射通量,系统包括两个相同的X射线探测器及相应滤膜。罗斯滤片法的优点在于利用相邻核素对X射线相似的阻止率,可滤出一个窄的能带并去除高能部分的干扰,获得了Ti平面靶K壳层X光辐射产额。实验结果表明:硬X射线能段在4.5~4.9keV之间的K壳特征辐射占优,连续谱所占份额较低(与晶体谱仪一致);随着激光能量的增加,特征辐射增加;激光强度接近2×1015 W/cm2时,能量转换效率出现峰值。

Measurement of X-ray produced from laser irradiating solid target using Ross filter method

Flux of X-ray produced from focussing laser radiation onto solid target was measured using a Ross filter system. The system consists of two identical X-ray detectors, appropriate filters mounted ahead of each detector. Ross filter method uses the advantages of the X-ray nuclide adjacent similar rejection, can filter out a narrow-band interference and remove high-energy part of the plane to get the Ti target K-shell X-ray radiation yield. Experiment result shows that k-shell emission of 4.5-4.9 keV prevails over continuum spectra (coincidence with result from crystal spectrometer). Characteristic emission increases with increased laser energy and a peak in conversion efficiency appears near 21015 W/cm2.