电子碰撞激发类氖锗X光激光增益饱和的理论研究  

THEORETICAL STUDIES OF GAIN SATURATION FOR THE ELECTRON COLLISIONAL EXCITATION NEON LIKE Ge X-RAY LASER SCHEME

作　　者：王光裕[1] 

机构地区：[1]北京应用物理与计算数学研究所

出　　处：《强激光与粒子束》1995年第2期295-303,共9页High Power Laser and Particle Beams

基　　金：国家高技术计划激光技术专题资助

摘　　要：耦合ｘ光激光辐射输运方程与速率方程，编制了研究类氖锗等离子体中多条激光线增益饱和过程的程序。计算结果与普通饱和方程的结果在深度饱和阶段有显著区别。计算结果还显示了增益曲线“烧孔”及线宽在饱和前后由不断变窄到不断加宽的现象。理论结果与“多靶串接”类氖锗Ｘ光激光实验数据进行了比较。Abstract We study the gain saturation process for the electron collisional excitation Ne-like GeX-ray laser scheme by coupling the radiation transport equation of X-ray lasers and rateequations, dominating population of levels.We have assumed the gain region, in which X-ray lasers propagate and amplify,is auniform cylindrical plasma, refraction of X-ray radiation is neglected. In the gain region,electron temperature, electron density, ion temperature, fraction of Ne-like ion and F-likeion are given constant. The photons of every lasing line is divided into 201 groups. Thehomogeneously and inhomogeneously broadening of lasing lines were considered. Ne-likeions and F-like ions also are divided into 201 groups according to thermal velocity. Thepopulddtion inversions calculations were based on the steady-state rate equations including37 levels of Ne-like ions and 3 lowest levels of F-like ions.In rate equations, the processof electron collisional excitation and deexcitation, spontaneous emission, dielectronicrecombination from F-like ions to Ne-like ions,stimulated emission, and absorptioncaused by lasing lines, were included. In order to account trapping effect, sevenspontaneous emission coefficients are multiplied by the escape probabilities. The simulated results were compareded with calculation of the usual saturation equation for sin-gle independent laser. In deep saturation stage great differences have been found: the gain of 19.6,23.2, 23.6, 28.6nm lasers drop with increasing target length L more rapidly (see Fig.3). The gainof 19.2, 24.7nm lasers vary from positive to negative with increasing L (see Fig.6). When Lis about 11cm, the integrated intensity of 19.6nm line surpass the 23.6nm line (see Fig.1), thecentral-of-spectrum intensity of 19.6nm line also surpass 23.2, 23.6nm lines (see Fig.8). AfterLgreater than about 7cm, the ratio of intensity of the 23.2nm line and 23.6nm line is about 2 (seeFig.8). These results is similar to results of gain saturation experiment of the Ne-like Se X-raylasers at LLNL�

关 键 词：X光激光 类氖锗 增益饱和 电子碰撞激发 

分 类 号：TN241[电子电信—物理电子学]