Characterization of Cable Gun Plasma with a Charge Collector Array

The density,drift velocity and reproducibility of the plasma produced by a cable plasma gun array have been measured with a charge collector array,The plasma is used to prefill a coaxial plasma-opening switch with a conducting time approaching 0.4us,The reproducibility of the plasma source in subsequent shots is better than 5%.Near the gun nozzle and the opposite electrode,the plasma density amounts to 10^15cm%-3,which is 2 times to 3 times that in the gap between the two coaxial electrodes.A plasma drift velocity of about 2.4cm/μs is observed from the time of flight of the charged particles.Both plasma density and drift velocity increase almost linearly with the rise in charge voltage.     

Experimental Study of the Multi-gap Multi-channel Gas Spark Closing Switch

1. IntroductionHigh-voltage and high--current closing switch is oneof the key elements in pulsed-power systems. It hasextensive applications in generating high--voltage andhigh-current pulses With the recent development ofpulsed-X-r8y simulator and high--power Z--pinch tech-nology [l,2], it is required that the closing switch is ofsmall inductance, low jitter, high conducting currentand long operating life.One of the methods for the reduction of switchlnductance, jitter and electrode erosion …     

Comparative study on breakdown characteristics of trigger gap and overvoltage gap in a gas pressurized closing switch

Gas pressurized closing switches are one of the most important elements in FLTD-based systems. Improving the trigger performance of gas switches is useful for optimizing the output parameters and the reliability of the FLTD. In this paper, the breakdown characteristics of the trigger gap and the overvoltage gap are studied experimentally. The reasons for the different breakdown performance of the two gaps are also investigated. The results show that the breakdown delay of the trigger gap is more influenced by the trigger voltage, while the breakdown delay of the overvoltage gap is more influenced by the working coefficient and always higher than that of the trigger gap. The jitter of the trigger gap is more influenced by the trigger voltage and accounts more than 60% of the total switch jitter, while the jitter of the overvoltage gap is hardly changed with the trigger voltage as well as the working coefficient and maintains less than 1.4 ns. It is proved that the discharging product from the trigger gap can effectively reduce the breakdown delay and jitter of the overvoltage gap. Based on that, the effect and improvement of pre-ionization on the two gaps are also studied. It is concluded that the jitter of the trigger gap reduces obviously when the pre-ionization is added, while the pre-ionization almost has no effect on the jitter of the overvoltage gap. The jitter of the overvoltage gap is about two times higher than the trigger gap in the pre-ionizing switch.     

单/双路馈入磁绝缘感应电压叠加器感应腔角向传输线的优化

角向传输线作为磁绝缘感应电压叠加器(MIVA)感应腔的关键部件,对MIVA感应腔馈入电流角向均匀分布,以及感应腔输出响应有决定性影响。为此,从馈入电流角向分布、阻抗匹配、绝缘安全等方面阐述了MIVA感应腔角向传输线的物理设计原则。针对双路和单路两种脉冲馈入方式,分别给出了优化的角向传输线结构。采用3维全尺寸、瞬态电磁模型对馈入电流角向分布和感应腔输出脉冲进行了模拟计算。结果表明,双路馈入MIVA感应腔馈入电流均匀性较好,设计角向传输线时首要考虑因素是降低角向线阻抗来改善感应腔输出脉冲响应,减小输出波形畸变。单路馈入MIVA感应腔馈入电流不均匀程度显著增大,采用非对称的角向线结构可提高馈入电流均匀性。双路和单路馈入MIVA感应腔电流角向不均匀系数最低分别为3%和9%。     

带外加磁场的微秒级等离子体断路开关

简述了脉冲功率电感储能技术中带外加磁场的微秒级等离子体断路开关 (MPOS)的发展现状 ,对磁场控制POS的工作机理、电极极性效应作了简单的分析。     

一种多间隙气体开关击穿特性的实验研究

快前沿直线型变压器驱动源(FLTD)是一种可以直接获得100 ns脉宽的脉冲功率源新技术,在Z箍缩、闪光照相、强激光和高功率微波方面具有重要应用。为了寻求用于FLTD的多间隙气体开关的合适结构,设计了一种场畸变多间隙气体开关。该开关含有6个间隙,各个间隙距离相等,开关间隙总长度为30 mm。开关中间电极为锚式固定结构,每个电极由3只螺钉固定在绝缘筒壁内侧,数值计算了开关的电场分布,实验研究了开关的自击穿及触发特性。结果表明,开关自击穿特性曲线与经验公式曲线基本符合,自击穿电压的分散性<3.2%;在工作系数为50%时,开关仍能正常触发,触发时延约百ns;在工作系数为60%时,触发脉冲为150 kV/15 ns的情况下,开关触发时延约60 ns,抖动时间约5 ns。     

Influences of Switching Jitter on the Operational Performances of Linear Transformer Drivers-Based Drivers

A whole circuit model of a linear transformer drivers (LTD) module composed of 60 cavities in series was developed in the software PSPICE to study the influence of switching jitter on the operational performances of LTDs. In the model, each brick in each cavity is capable of operating with jitter in its switch. Additionally, the manner of triggering cables entering into cavities was considered. The performances of the LTD module operating with three typical cavity-triggering sequences were simulated and the simulation results indicate that switching jitter affects slightly the peak and starting time of the output current pulse. However, the enhancement in switching jitter would significantly lengthen the rise time of the output current pulse. Without considering other factors, a jitter lower than 10 ns may be necessary for the switches in the LTD module to provide output current parameters with an acceptable deviation.