Experimental characterization of a transition from collisionless to collisional interaction between head-on-merging supersonic plasma jetsa)
Experimental characterization of a transition from collisionless to collisional interaction between head-on-merging supersonic plasma jetsa)
复制标题
正面合并超音速等离子体射流之间从无碰撞到碰撞相互作用转变的实验表征a)
DOI：
10.1063/1.4920955
复制
发表时间：
2014
影响因子：
2.2
通讯作者：
S. Hsu
中科院分区：
文献类型：
--
作者：
A. Moser;S. Hsu
我们目前的结果从实验上的头上合并的两个超音速等离子体射流在最初的碰撞制度的逆流离子。等离子体射流是氩气/杂质或氢气/杂质混合物，由脉冲功率驱动的轨道炮产生。基于时间和空间分辨的快速成像，多弦干涉，并调查光谱测量的重叠区域之间的合并射流，我们观察到，射流最初相互渗透，与计算的射流间离子碰撞长度，这是长的。当喷流相互渗透时，平均电荷状态的上升导致喷流间离子碰撞长度迅速减小。最后，相互作用变成碰撞，喷流停滞，最终产生与碰撞冲击一致的结构。这些实验观测可以帮助验证等离子体碰撞和电离模型与复杂的状态方程的等离子体。
We present results from experiments on the head-on merging of two supersonic plasma jets in an initially collisionless regime for the counter-streaming ions. The plasma jets are of either an argon/impurity or hydrogen/impurity mixture and are produced by pulsed-power-driven railguns. Based on time- and space-resolved fast-imaging, multi-chord interferometry, and survey-spectroscopy measurements of the overlapping region between the merging jets, we observe that the jets initially interpenetrate, consistent with calculated inter-jet ion collision lengths, which are long. As the jets interpenetrate, a rising mean-charge state causes a rapid decrease in the inter-jet ion collision length. Finally, the interaction becomes collisional and the jets stagnate, eventually producing structures consistent with collisional shocks. These experimental observations can aid in the validation of plasma collisionality and ionization models for plasmas with complex equations of state.