“强光一号”等离子体开关及负载稳定性分析

"强光一号"等离子体断路开关(POS)及负载二极管系统工作性能不够稳定,通过分析数据指出POS等离子体源参数差异性是导致系统不稳定的主要原因。POS等离子体源参数重复性测量结果表明,在开关断路时刻等离子体源瞬时发射等离子体密度重复性极差在10%左右,而开关区间累积等离子体密度极差超过100%。开关区间累积等离子体密度和阴极重粒子发射会对POS断路性能产生显著影响。计算表明开关区间累积等离子体密度差异对POS断路电流阈值影响达到200kA,与运行数据统计结果一致;在断路电流阈值相同的条件下,阴极物质逸出对二极管电压影响显著,MCNP程序计算结果表明,产生辐射剂量差别可以达到80%,与统计数据相当。

Experimental study on performance parameters of plasma source for the plasma opening switch on QiangguangⅠgenerator

Statistic result of experiment data of Qiangguang Ⅰ plasma opening switch (POS) and diode shows that the POS-diode system is not stable. The system instability is induced by the dispersing ejection parameter of the POS plasma source. Plasma source ejection parameter measurement shows that the stability of plasma ejection density as the POS is opening is fine. Range of it is less than 10% but range of the cumulated plasma density in switch zone is more than 100%. POS performance has been obviously influenced by the cumulated plasma density in switch interval and the cathode matter ejection. Calculated result shows that range of the cumulated plasma density change the POS breaking current by more than 200 kA, which is close to the statistic result. Effect of cathode material on the opening performance is notable. Because of it, diode dose might fall 80% with the same breaking current according to MCNP calculation and the experiment result.