气体开关串级环形间隙放电相互影响机制研究

针对中空和非中空触发电极结构的两间隙开关，进行了触发击穿特性实验，对比两个间隙的击穿抖动和通道数，分析了串级两间隙的相互影响机制。实验结果表明：两只开关触发间隙击穿抖动和通道数变化规律基本一致；非中空开关自击穿间隙击穿抖动随工作系数的增大而减小，最小约3 ns，中空开关自击穿间隙击穿抖动始终约1 ns；非中空开关自击穿间隙难形成多通道放电，中空开关自击穿间隙通道数明显多于其他间隙。触发间隙首先放电产生紫外光，通过触发电极中空通孔预先照射自击穿间隙产生初始电子，是自击穿间隙击穿抖动减小、通道数增加的主要作用机制。     

气体开关触发间隙与过压间隙击穿特性研究

为研究快脉冲直线变压器驱动源（FLTD）多间隙气体开关的触发击穿特性，针对一种环形电极两间隙等效实验开关，开展不同触发电压、工作系数和电极材料下的击穿特性实验，对比两个间隙的击穿延时和抖动，分析间隙击穿特性的主要影响因素和作用机制。实验结果表明：触发间隙击穿延时主要受触发电压影响，而工作系数是过压间隙击穿延时的主要影响因素；开关抖动主要来自于触发间隙，触发间隙抖动随触发电压的增大明显减小，过压间隙抖动基本不随触发电压和工作系数变化且维持在较低值；石墨电极开关的击穿延时和抖动明显小于不锈钢、黄铜和钨铜电极开关，具有良好的触发击穿性能。通过分析指出，是否有预电离可能是两个间隙击穿特性差异的主要原因。     

Modeling Methods for the Main Switch of High Pulsed-Power Facilities Based on Transmission Line Code

Based on the transmission line code （TLCODE）, a circuit model is developed here for analyses of main switches in the high pulsed-power facilities. With the structure of the ZR main switch as an example, a circuit model topology of the switch is proposed, and in particular, calculation methods of the dynamic inductance and resistance of the switching arc are described. Moreover, a set of closed equations used for calculations of various node voltages are theoretically derived and numericMly discretized. Based on these discrete equations and the Matlab program, a simulation procedure is established for analyses of the ZR main switch. Voltages and currents at different key points are obtained, and comparisons are made with those of a PSpice L-C model. The comparison results show that these two models are perfectly in accord with each other with discrepancy less than 0.1%, which verifies the effectiveness of the TLCODE model to a certain extent.     

Criterion of Magnetic Saturation and Simulation of Nonlinear Magnetization for a Linear Multi-core Pulse Transformer

The linear multi-core pulse transformer is an important primary driving source used in pulsed power apparatus for the production of dense plasma owing to its compact,relatively low-cost and easy-to-handle characteristics.The evaluation of the magnetic saturation of the transformer cores is essential to the transformer design,because the energy transfer efficiency of the transformer will degrade significantly after magnetic saturation.This work propses analytical formulas of the criterion of magnetic saturation for the cores when the transformer driver practical loads.Furthermore,an electric circuit model based on a dependent source treatment for simulating the electric behavior of the cores related to their nonlinear magnetization is developed using the initial magnetization curve of the cores.The numerical simulation with the model is used to evaluate the validity of the criterion.Both the criterion and the model are found to be in agreement with the experimental data.     

MV级电爆炸导体开关输出脉冲的数值模拟与实验

介绍用电爆炸导体开关产生 ＭＶ级高压脉冲的方法,建立了开关的计算模型,给出了与电感储能系统耦合时,开关上电流电压波形的计算结果与实验结果。     

百千安电流下的单丝Z箍缩实验研究

为更深层次理解Z箍缩基本物理过程，认识单丝早期演化对丝阵后续内爆过程产生的影响，基于百千安直线脉冲变压器（FLTD）平台开展了不同材料（钨丝、镀膜钨丝和铝丝）单丝Z箍缩实验研究，实验获得了单丝演化过程的双分幅激光阴影和干涉图像。实验发现：初始直径相同（15 μm）的条件下，铝丝核的膨胀速度比钨丝核的快，在电流开始一段时间内，铝丝核沿轴向呈均匀膨胀，而钨丝核因电极效应沿轴向膨胀不均；镀膜钨丝（15 μm W+2 μm Polyimide）核的膨胀速度远大于钨丝核的，甚至高于铝丝核的，同时镀膜还降低了消融等离子体不稳定性的发展速度。     

Al丝物理状态调控及对芯晕演化特性的影响

基于快直线脉冲变压器(FLTD)平台开展了数十kA电流下Al单丝芯晕演化特性研究，实验发现丝过早发生电压击穿会减少丝芯的能量沉积，而晕等离子体的迅速发展将约束丝芯的进一步膨胀，降低丝芯膨胀速度。通过调整负载两端的初始电压、丝长及增加闪络开关等手段，抑制了Al丝的过早击穿，增加了早期能量沉积，获得了不同的丝芯物理状态（部分气化或完全气化）。Al丝的气化提高了丝芯膨胀速度，最高达11~14 km/s，晕等离子体发展缓慢，延缓了边界处不稳定性的出现，降低了后期m=0的发展速度。FLTD负极性输出时，Al丝沿轴向的极性效应更加明显，靠近阴极处丝芯膨胀慢，边界处晕等离子体密度高，不稳定性的发展速度快。     

直线脉冲变压器技术回顾与展望

直线脉冲变压器是近年来发展最迅速的高功率脉冲驱动源.介绍了快放电直线脉冲变压器的应用前景、工作原理,回顾了直线脉冲变压器的技术发展历程,分析了不同时期的结构特点,阐述了开关、触发系统、磁芯等关键技术研究现状和今后研究重点.最后总结了直线脉冲变压器发展动向及可能涉及的相关技术.     

An Experimental Study on Kr Gas-puff Z-pinch

Kr gas-puff Z-pinch experiment performed recently on Qiang-uang I pulsed power generator is reprted.The generator has a 1.5MA current with a pulse width of 100ns.The total X-ray energy as well as its spectrum has been obtained.and the average power of X-ray radiation in 50-700eV measured by XRDs is 2 TW.The generator configuration.gas-puff load assembly and diagnostic system for the experiments are described.     

Primarily Experimental Results for a W Wire Array Z Pinch

Primarily experimental results are given for a W wire array Z pinch imploded with up to 2 MA in 100 ns on a Qiangguang-I pulsed power generator. The configuration and parameters of the generator, the W wire array load assembly and the diagnostic system for the experiment are described. The total X-ray energy has been obtained with a averaged power of X-ray radiation of 1.28 TW.