摘要
用一维非平衡辐射流体力学程序JB19对激光照射Au、Se、Ge、Cu等靶进行了模拟计算,并对形成的等离子体状态做了详细描述。计算表明只要选取适当的激光介质(包括材料、形状和结构)和相匹配的激光条件就可以得到产生粒子数反转和激光增益的最佳等离子体状态。计算结果与LLNL(劳伦斯利弗莫尔实验室),NRL(海军实验室),CEL(里梅尔实验室)实验观察值符合得很好。
The dynamics conditions of laser -produced plasmas have been analyzed and studied in detail using JB19 computer code, a non -LTE radiative hydrodynamic code of one-dimensional geometry. Using the code we can simulate the interactions of laser beams with targets. When a laser beam of 0.53μm with pulse duration of 450ps and intensity of 1014W/cm2 for single-sided irradation (5×1013W/cm2 for double-sided irradiation) is used to irradiate 750A selenium foil deposited on a 1500A formvar substrate, JB19 simulation predicts that the smooth electron density profile is over a distance of 100μm, the electron temperature Te and ion temperature T. are 0.9keV and 0.5keV respectively, electron density Ne, is about 3-5×1020cm-3. abundance of Ne-like ions is more than 25% and the lasting time of smooth density profile is over 100ps. When a laser beam of 1.06μm with a pulse duration of Ins, intensity of 7 ×1012W/cm2 and total energy of 840J is used to irradiate Ge target of 500A deposited on 1000A formvar. JB 19 simulati o gives the results of Nt=2- 3×1020cm-3, Tt =7-8 × 106K. When a laser beam of 1.06μm with a pulse duration of 2ns irradiates Cu target, we have the results of Ne = 1-2 × 1020cm-3. T=5 × 106Kand abundance of Ne-like ion 15-20%.
Computational results show that for a target of a medial Z element, irradiated by a laser beam of 1.06μm, a power density of 0.7- 1.4× 1015W/cm2 and a pulse duration of 1- 2ns are necessary to demonstrate 3p -3s population inversion and certain gain of soft X-ray laser.
出处
《强激光与粒子束》
EI
CAS
CSCD
1990年第3期298-310,共13页
High Power Laser and Particle Beams
关键词
电子
碰撞
激发
软X光
激光
JB19 code, simulation, soft x -ray laser, collisional excitation
