作为X激光增益介质的激光等离子体特性

本文报道利用具有空间分辨能力的透射光栅谱仪对以三体复合泵浦实现锂离子(Si~(11+)X光自发辐射放大的增益介质——硅激光等离子体特性的研究。结果表明,等离子体5～100A范围软X线辐射主要来自类氦离子(Si~(12+))到(S~(11+))复合辐射和Si~(11+)(n=3→n=2)跃迁发射的贡献,且它们辐射的最大强度距靶面130μm,对应的电子密度3×10~(20)cm~(-3)与Si~(11+)+1s~23d能级的粒子数相对丰度比36;实验中还观察到Si~(11+)(1s~23d-1s~22p)跃迁发射存在着明显的自吸收现象。

Characteristics of line-focused laser-produced plasma as an X-ray gain medium

This paper presents our experimental investigation on the characteristics of laser produced silicon plasma column as an X-ray gain medium in which the soft X-ray spontaneous emission amplification is demonstrated succesfully. It is found that the soft X-ray emission from 5A～100A of the plasma under this condition is mainly contributed from the He-like (Si12+) ions to Li-like (Si11+) ions recombination radiation and the Li-like ions n=3-n=2 transition emission and the strongest emissions occur at about 130μm from the target surface, with the corresponding electron density 3×1020 /cm3. The average ratio of the He-like ions to the Li-like ions on the 1S23d level is about 36. The reabsorption of the Si11+1s23d-1s22p transition is also observed of experimentally.