超高速碰撞2024-T4铝靶产生的膨胀等离子体云的电磁特性

Electromagnetic characteristics of expanding plasma cloud created by hypervelocity impact

针对超高速碰撞产生的瞬态等离子体的特点,利用建立的扫描朗缪尔探针、朗缪尔三探针诊断系统及线圈系统,测量了超高速碰撞喷出物产生的膨胀等离子体云中等离子体的特征参量和磁感应强度。在传感器布局和方位角固定的前提下,进行了2种碰撞速度、相同入射角度条件下2024-T4铝弹丸超高速碰撞2024-T4铝靶产生的膨胀等离子体云电磁特性的实验室测量。实验结果表明,碰撞产生的等离子体的平均电子温度为0.4～0.9eV,电子密度在1012 cm-3量级,线圈的磁感应强度幅值为10～20nT。通过数据处理,获得了2种实验条件下整个物理过程在给定探针、线圈位置处等离子体的电子温度、电子密度和磁感应强度与碰撞速度的关系,并对扫描朗缪尔探针和朗缪尔三探针的测量结果进行了比较。

According to the characteristics of transient plasma ejectors created by hypervelocity impact,the sweep Langmuir probe,the triple Langmuir probe and the coil measurement systems were established to measure the plasma characteristic parameters as well as the magnetic induction intensity in expanding plasma cloud.Based on the given layout and azimuth angle of the sensors,the electromagnetic characteristic measurements of expanding plasma cloud generated by the impact of 2024-T4 aluminum projectiles against the 2024-T4 aluminum targets in the laboratory were carried out at the two impact velocities.Experimental results show that the average electron temperature,electron density,and magnetic induction intensity amplitude value are 0.4~0.9 eV,on the order of 1012 cm-3 and 10~20 nT,respectively.By processing the experimental data,the relationships between electron temperature,electron density and magnetic induction intensity were obtained,respectively,at the given positions of the probes and coils during the whole physical process for the two experiments.And the results measured by the sweep Langmuir probe and the triple Langmuir probe were compared.