Secondary shock formation in xenon-nitrogen mixtures
Secondary shock formation in xenon-nitrogen mixtures
复制标题
氙氮混合物中二次激波的形成
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
T. Ditmire
中科院分区：
文献类型：
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作者：
J. F. Hansen;M. J. Edwards;D. Froula;A. Edens;G. Gregori;T. Ditmire
研究了不同不透明度和热容的介质中激波的扩展，通过混合氙气和氮气保持质量密度恒定，系统地改变了这些介质中的冲击波的扩展。初始激波是通过在被氙氮混合物包围的针尖上短暂(5 Ns)沉积激光能量(5J)而产生的。最初的激波是球形的，辐射的，马赫数很高，它把超音速辐射驱动的热波送到远远超过它自己的地方。当热波相对于下游等离子体的马赫数降至∼2时，热波变为烧蚀型，并在其前面驱动第二个激波，以满足热波参考系中的质量和动量守恒。这一系列事件的细节取决于周围介质的不透明度和热容量等。在从100%Xe质量分数到100%N_2质量分数的整个范围内观察到了二次激波的形成。TH的形成半径。
The expansion of shock waves has been studied in mediums with different opacities and heat capacities, varied in systematic ways by mixing xenon with nitrogen keeping the mass density constant. An initial shock is generated through the brief (5ns) deposition of laser energy (5J) on the tip of a pin surrounded by the xenon-nitrogen mixture. The initial shock is spherical, radiative, with a high Mach number, and it sends a supersonic radiatively driven heat wave far ahead of itself. The heat wave rapidly slows to a transonic regime and when its Mach number drops to ∼2 with respect to the downstream plasma, the heat wave becomes of the ablative type, driving a second shock ahead of itself to satisfy mass and momentum conservation in the heat wave reference frame. The details of this sequence of events depend, among other things, on the opacity and heat capacity of the surrounding medium. Second shock formation is observed over the entire range from 100% Xe mass fraction to 100% N2. The formation radius of th...