160 kV,10 ns上升沿脉冲触发器的研制

Development of Pulsed Trigger in 160 kV and 10 ns Raise Time

为了研究医学系统中乳腺癌早期诊断的关键技术,本文研制了一台用于准点X光相位差照相系统的触发器,对触发器的输出脉冲要求:峰值电压160 kV,上升时间 ≤ 10 ns,脉宽 ≤ 100 ns。该触发器由Marx发生器、火花隙开关、电容分压器及输出段构成,其中Marx发生器采用8级同轴正负极充电的双边结构,每级由6个40 kV 3800 pF的陶瓷电容器并联组成,采用紧凑回路低电感的设计;4个火花隙开关采用跨级触发放电;在输出段末端设计了环形电容分压器作为触发器的高电压测量探头。Simplorer模拟结果表明:在实际负载阻值时,输出电压169 kV,上升时间 ≤ 10 ns,脉宽 ≤ 100 ns,满足设计指标要求。

In order to study the key technology of early diagnosis of breast cancer in medical system, a trigger for the X-ray phase-contract imaging system is developed. The output pulse of the trigger is required: the peak voltage = 160 kV, the rise time ≤ 10 ns, and the pulse width ≤ 100 ns. The flip-flop consists of Marx generator, spark gap switch, capacitive voltage divider and output section. The Marx generator is composed of 8 stages of coaxial positive and negative electrode charge, each level is composed of 6 40 kV 3800 pF ceramic capacitors in parallel, and the design of compact loop low inductance is adopted;and the 4 spark gap switches use the cross stage trigger discharge. At the end of the output section, a ring capacitance divider is designed as a high voltage probe for triggers. The Simplorer simulation results show that when the actual load is blocked, the output voltage is 169 kV, the rise time is less than 10 ns, and the pulse width is less than 100 ns, which meets the design requirements.