基于共用腔体与内置触发的12级串联太瓦级LTD脉冲源

Twelve-Stage Linear Transformer Driver With One Terra-Watts Power on a Sharing Common Cavity Shell and Internal in-Situ Triggering Method

利用共用腔体新型拓扑结构与内置时序触发新方法,给出了12级串联太瓦级LTD脉冲源的结构和连接假负载的调试结果。12级LTD设计指标:驱动匹配负载时的输出峰值电压为1 MV,峰值电流为1 MA,脉冲前沿小于150 ns,直径为2.5 m,长度为4.8 m。12级串联模块分为3组,初级共用圆柱形外腔体,采用SF6气体绝缘。LTD次级内筒为圆锥型,阻抗逐级与初级源匹配。LTD内的276只5 GW开关采用内置时序触发新方法,每级由内置的1个触发支路产生电脉冲,实现23个主放电支路同步触发放电,组内采用高压延时线按理想时序触发每级LTD触发支路,组间由紧邻上游组件的第一级触发支路产生电脉冲经高压线级联触发组件内的每级触发支路。外部仅引入1路触发脉冲和3组±100 kV高压充电电缆。实验结果验证了共用腔体、分立柱回流和插拔支路的新型拓扑结构及内置时序触发新方法的技术可行性。当充电电压为±83 kV,驱动电感为40 nH,串联匹配负载约为0.7Ω时,负载峰值电压为1.0 MV、峰值电流为1.0 MA、前沿(0.1~0.9)约为75 ns。本文提出的共用腔体拓扑结构和大规模气体开关内置同步时序触发方法为建立电流为数十兆安和峰值功率为数百太瓦的LTD型Z箍缩脉冲驱动源提供了一种全新技术方案。

The configuration and experimental results of 12-stage linear transformer driver(LTD)are presented in this paper.The innovative technology of the 12-stage LTD shares a common cylindrical cavity shell and internal in-situ triggering brick and high voltage delay line,which realizes the ideal time sequence triggering for large-scale gas switches of LTD.The design parameters of 12-stage LTD are the peak voltage of 1 MV,the peak current of 1 MA,and the pulse rise time less than 150 ns.The 12-stage LTD with the diameter of 2.5 m and the length of 4.8 m is developed.The 12 level series modules are divided into 3 groups,and the primary shares a cylindrical outer chamber,which is insulated with SF6 gas.The secondary of LTD adopts the deionized water-insulation transmission line with a conical profile structure to match the gradually changing primary impedance.The 276 gas spark switches of LTD are triggered with the novel method of internal in-situ triggering in sequence previously presented at home and abroad.Every stage of LTD is laid a triggering brick generating the pulse with fast rise time and high amplitude realizing the 23 main bricks discharging in synchronization.The triggering bricks for every group of LTD are triggered by a high voltage delay line with isolation resistors from the external input high voltage cable or the first stage triggering brick of the upstream group.So the 12-stage LTD needs only one input triggering pulse and three sets of high voltage charging cables of±100 kV while the general method with one stage and one separate cavity needs 48 input pulses and 12 sets of high voltage charging cables of±100 kV.The experimental results of 12-stage LTD verify the validity of sharing a common cavity cylinder for all stages in series and the in-situ triggering method in sequences.When the charging voltage of±83 kV and the load matched impedance of 40 nH and 0.7Ω,the output peak voltage is 1 MV,the peak current is 1 MA,and the rise time of the pulse is 75 ns for 12-stage LTD.The topology based on sharing a common cavity shell and the located in-situ triggering in sequence provides a new technique for constructing the large-scale LTD-based Z pinch accelerators with the output current of several tens of MA and the power of hundreds of terra-Watts.