多级串联磁绝缘感应电压叠加器脉冲输出特性研究

Magnetically-insulated-induction-voltage adder (MIVA) is a classic source that can provide pulse X-ray with the smaller spot and the higher dose rate. It has been widely used for the diagnoses of hydrodynamic phenomena under conditions of the extreme energy density. To obtain the high voltage and current that desired for radiograph diodes, multi-stage cavities are always needed. But the pulse waveform of multi voltage additions has great effects on qualities of the output X-ray. In this project, a full TLCODE circuit model of MIVAs with tens of cavities connected in series will be studied. Effects of the cavity-driving sequences and jitters on the performance of MIVA output voltages will be quantificationally analyzed. In allusion to the driving desire of radiograph diodes, a method will be studied and given for the choice of the optimizing driving sequence. Based on technologies of impedance transform lines (ITL) and magnetically-insulated transmission lines (MITL), a new structure of the secondary-coil will be explored to obtain optimized performances of the coupling, addition and transmission efficiencies, and testing experiments will also be conducted. Based on the MIVA stand with 2 to 3 cavities, effects of the cavity-driving sequences, jitters and impedance transform profiles on characteristics of the MIVA output will be experimentally studied, and the TLCODE model will also be tested and revised.

磁绝缘感应电压叠加器（MIVA）是一种产生小焦斑、高剂量脉冲X射线的典型驱动源技术，广泛应用于极端能量密度条件下材料流体动力学现象诊断领域。为获得二极管驱动所需的高电压、大电流，MIVA需采用多级感应腔串联，但多级脉冲电压叠加波形对其X射线输出特性具有决定性的影响。本项目拟研究数十级感应腔串联MIVA驱动源TLCODE全电路模型；定量分析多级感应腔串联脉冲馈入时序和抖动对MIVA输出脉冲波形（包括前沿时间、平顶时间、幅值等）及其工作状态的影响；针对二极管驱动参数需求，给出多级感应腔串联脉冲馈入时序优化方法；基于变阻抗传输线技术和磁绝缘传输线技术，探索一种具有更优能量耦合、叠加和传输特性的次级结构，开展其原理性验证实验；基于2至3级感应腔串联MIVA平台，实验研究脉冲馈入时序及其抖动、次级阻抗变换形式等因素对MIVA脉冲输出特性的影响，同时，检验并修正所建TLCODE全电路模型。

磁绝缘感应电压叠加器（MIVA）是一种产生小焦斑、高剂量脉冲X射线的典型驱动源技术，广泛应用于极端能量密度条件下材料流体动力学现象诊断领域。为获得二极管驱动所需的高电压、大电流，MIVA需采用多级感应腔串联，但多级脉冲电压叠加波形对其X射线输出特性具有决定性的影响。. 本项目建立了数十级感应腔串联MIVA驱动源TLCODE全电路模型；定量分析多级感应腔串联脉冲馈入时序对MIVA输出脉冲波形（包括前沿时间、平顶时间、幅值等）及其工作状态的影响，提出通过脉冲时序控制实现输出波形调控方法；理论推导给出了脉冲馈入时间抖动与输出脉冲前沿的函数关系，并充分考虑的串联级数的影响；以X射线辐射剂量率最大化为目标，给出多级感应腔串联次级阻抗优化方法；基于变阻抗传输线技术和磁绝缘传输线技术，提出一种标准指数型阻抗变换形式的次级磁绝缘传输线，计算结果表明，其具有更优能量耦合、叠加和传输特性；基于2级感应腔串联MIVA平台，实验研究了脉冲馈入时序及其抖动、次级阻抗变换形式等因素对MIVA脉冲输出特性的影响，同时，检验并修正了所建TLCODE全电路模型的有效性。