本文主要研究了超强超短激光与Ar团簇相互作用过程中X射线能谱、K壳层光子产额、能量转换效率以及激光对比度对X射线光子产额的影响.实验中得到K壳层的光子产额约为1×10~(11)/发,能量转换效率约为2.8×10~(-5).同时观测到较强预脉冲离化团簇会导致预电离,产生膨胀等离子体,然而主脉冲与膨胀的等离子体相互作用的强度较未膨胀时降低了,从而导致K壳层光子产额降低,而使用高对比度的激光能增加X射线光子产额.
Bright K-shell X-ray emissions are generated through the interaction between intense femtosecond laser pulses and Ar clusters. The total yield of K-shell X-ray photons reaches 1×10~(11) photons/shot with a conversion efficiency of 2.8×10~(-5) in 4π.When Ar clusters are irradiated by a laser pulse with intense prepulse,the yield of K-shell X-ray photos will decrease due to prepulse ionization. Keeping high-density plasmas interacting with the main pulse is essential for obtaining the highest X-ray yield.