Ion energy spectrum of expanding laser-plasma with limited mass
Ion energy spectrum of expanding laser-plasma with limited mass
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DOI：
10.1063/1.1928247
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发表时间：
2005-06-01
影响因子：
2.2
通讯作者：
Nishimura, H
中科院分区：
文献类型：
--
作者：
Murakami, M;Kang, YG;Nishimura, H
给出了有限质量激光等离子体流体力学膨胀的一个简单解析模型，它在激光照射过程中准等温膨胀，关断激光后准绝热膨胀。在等温膨胀过程中，物质在相对较长的激光脉冲下完全解体，而离子则保持加速。这一物理图景与半无限平面稀疏波的正统自相似解所描述的情况形成了显著的对比。分别用不同的自相似解描述了这两个连续的展开，即等温膨胀和绝热膨胀，发现它们在时间和空间上是光滑联系的。由该模型得到的离子能谱很好地再现了不同几何条件下的实验结果。根据激光和靶参数估算了离子的最大动能。(C)2005年美国物理研究所。
A simple analytical model is presented for hydrodynamic expansion of laser-produced plasma with a limited mass, which expands quasi-isothermally during laser irradiation and quasiadiabatically after turning off the laser. During the isothermal expansion, the masses undergo entire disintegration under a relatively long laser pulse, while the ions are being kept accelerated. This physical picture significantly contrasts with that described by the orthodox self-similar solution for a semi-infinite planar rarefaction wave. The two successive expansions, i.e., isothermal expansion followed by adiabatic expansion, are described, respectively, by different self-similar solutions, which are found to be connected smoothly with each other in time and space. The ion energy spectrum obtained by the model reproduces well experimental results obtained under different geometrical conditions. The maximum ion kinetic energy is also estimated in terms of the laser and target parameters. (C) 2005 American Institute of Physics.