基于光导开关的Blumlein型PFN能量转换效率

摘要

A Blumlein-PFN (BPFN) was fabricated and the factors that affect energy transfer efficiency were investigated. The BPFN is composed of ceramic capacitor, aluminum strip and GaAs-PCSS. Air-gap was selected as the BPFN pulse forming switch first, then expected pulse width and BPFN's impedance were obtained, which confirms the effectiveness of our design. Experiments were conducted with GaAs-PCSS under different electric field and trigger laser energy. Results show that the loss induced by maintaining electric field is negligible when electric field is greater than 25 kV/cm and trigger laser energy of PCSS is between 3. 12 kV/cm and 4. 94 kV/cm. When trigger laser energy equals to 30. 4mJ and 3. 5 mJ, the energy efficiency of matched load is 62. 9% and 55% , and the equivalent connective resistance is 2. 3 Ω and 3. 13 Ω respectively. The connective resistance has been proved to be the most important factor which limits energy efficiency.%为了驱动低能重复频率高阻抗X光管,采用低感陶瓷电容构建了一套电长度约33.5 ns、阻抗约8Ω的Blumlein型脉冲形成网络(BPFN),在匹配负载条件下研究了采用GaAs光导开关(PCSS)作为脉冲输出开关时PCSS工作场强、激光触发能量与能量转换效率的关系.实验表明:PCSS截止场强为3.21～4.94 kV/cm,在工作场强高于20 kV/cm时,截止场强引起的能量损失对能量转换效率的影响不大；PCSS较高的导通电阻是影响PFN能量转换效率的主要因素,随着工作场强、激光触发能量的上升,能量转换效率呈指数上升趋势.