同轴圆柱形磁绝缘传输线前沿损失与工作电压关系

Pulse loss front in coaxial cylinder vacuum magnetically insulated transmission lines under different voltages

在磁绝缘传输线层流模型基础上,基于极限电流近似,推导获得了同轴圆柱形磁绝缘传输线在自磁限制绝缘时,前沿损失电子电流、功率的解析解.通过粒子模拟,获得了磁绝缘传输线在源阻抗不变的条件下,不同电压条件下的损失电子电流、损失功率.对比分析了模拟结果与极限电流近似下和最小电流近似下的理论结果.结果表明:损失电子电流与损失功率比例随电压增大而减小;电压高于4MV时,极限电流近似更符合模拟结果,电压大于10MV时,极限电流近似与模拟结果的相对误差从最小电流近似的50%以上减小到10%以下.对于建立磁绝缘传输线系统中,高压电脉冲从真空传输、磁绝缘传输线上传输到工作负载的全电路模拟具有一定的指导意义.

Based on the relativistic Brillouin flow theory, electron current and power loss in loss-front stage of coaxial cylinder vacuum magnetically insulated transmission line （MITL） are deduced under limiting current approximation. Through the particle-in-cell （PIC） model, loss currents and loss powers under different anode voltages are simulated. Simulation and theory results show that the pro- portions of loss current and loss power to the total current and power decrease when cathode-anode voltage increases. Beyond 4MV, limiting current approximation fits simulation results better than minimum current approximation. At voltages higher than 10 MV, relative error from limiting approximation is under 10%, while it exceeds 50% under minimum current approximation. This work is meaningful for establishing full circuit simulation of MITL system.