小型X-pinch装置的设计  

Design of Compact Table-top X-pinch Device

作　　者：杜彦强[1] 邹晓兵[1] 王新新[1] 曾乃工[1] 

机构地区：[1]清华大学电机系,北京100084

出　　处：《高电压技术》2009年第1期93-98,共6页High Voltage Engineering

基　　金：国家自然科学基金(10635050);全国优秀博士论文作者基金项目(200748);IAEA项目(14509)~~

摘　　要：X—pinch等离子体是一种高辐射强度的亚纳秒脉冲x射线点源，非常适合作为x射线相位差衬托照相的光源，因而在临床医学、生物科学上具有重要的应用前景。通常用于驱动的X—pinch装置的脉冲功率源体积庞大、造价较昂贵，难以满足方便使用的要求。为此，介绍了一台桌面型Xpinch装置的结构设计、参数计算及仿真。装置由Marx发生器、脉冲形成线、主开关和负载4部分构成。Marx发生器结构采用4台67nF／80kV电容器及2个三电极火化间隙开关构成的正负充电线路。电容器充电电压为60kV，初始储能480kJ，通过电缆将能量传到脉冲形成线。形成线选用以去离子水作为介质的同轴结构，长84cm，输出阻抗1．5Ω，预计装置的输出脉冲50ns，通过充以Nz气体的自击穿火花开关，将能量释放给负载。设计装置输出电流〉50kA，上升时间～50ns，输出功率约5Mw，适合驱动直径几pm的金属丝负载。整个装置可以放在1．8m×0．8m的带轮子的工作平台上，方便移动到各处进行X射线光相位差衬托照相。A dense hot X-pinch plasma, as a pointlike subnanosecond x-ray source with high brightness, is quite suitable for phase-contrast imaging including x-ray microscopy for biology and medicine. We designed a compact tabletop x-pinch device including the construction, calculation and emulation. The generator consists of a Marx generator, pulse-forming coaxial water lines, switch blocks and the load section. The Marx generator is composed of four 67 nF/80 kV capacitors and two triple-electrode switching circuits with both positive and negative charging. When working, each capacitor in the Marx generator is charged with 60 kV, and discharges to PFL （pulse forming line）, then to the load section through N2 spark gap. The PFL, with the output impendence of 1.5 Ω, is 84cm long corresponding to the output pulse of 50 ns. The original target was to develop a 100 kV, 50 kA system with 50 ns pulse rise time in order to satisfy a load of fine wire x-pinch with a few microns. The whole apparatus is placed in a flat worktable of 1.8 m 0.8 m with four wheels and can move everywhere conveniently.

关 键 词：X箍缩 X射线源 脉冲功率 小型装置 X射线照相 相衬法照相 

分 类 号：TN136[电子电信—物理电子学]