双丝耦合强度对Z箍缩电磁辐射的影响

Influence of coupling between two wires on electromagnetic radiation produced by Z-pinch

利用X 射线二极管、光电倍增管和B-dot探针测量了峰值220 k A ,0-100%上升时间100ns的脉冲电流驱动平行双丝产生的电磁辐射.实验结果表明,不同波段的电磁辐射具有不同的辐射机制,热辐射是产生X 射线的主要机制,可见光辐射来自热辐射和特征线辐射,微波辐射由非热电磁辐射机制产生.调节丝间距可改变双丝的耦合强度,当丝间距大于临界值时双丝解耦合,电磁辐射不依赖于丝间距;当丝间隙减小至低于临界值时,双丝耦合增强.增大双丝耦合强度不利于热辐射（X 射线和可见光）而有利于非热电磁辐射（ 微波）.对于单丝电流约100kA 、上升时间100ns的驱动条件,双丝解耦合的临界间距约为10mm ,双丝耦合强度对Z 箍缩在不同频段的电磁辐射有影响.丝阵由多根金属丝组成,其最小的相互作用单元可分解为双丝相互作用.

We have measured X-ray,optical and microwave radiations from two parallel wires driven by a current rising to220 kA in 100 ns.The experimental results imply that they are generated by different radiation mechanism.X-ray is generated by thermal radiation which is proportional to ohmic heating of wires.Optical radiation is from thermal emission and line emission,but microwave radiation is produced by non-thermal radiation.The dependence of radiation on distance between two wires demonstrates that increasing the coupling between two wires can enhance non-thermal radiation,but is detrimental to thermal radiation.For driving condition of 100 kA per wire used in our experiments,the critical distance where the two wires decouple is approximately 10 mm.It appears that the coupling between wires plays a fundamental role in electromagnetic radiation produced by Zpinch.