单孔柱 孔汇聚结构放电通道电阻率

Resistivity of Discharged Channel at Single-Hole Post-Hole Convolute

分析了柱-孔汇聚结构放电通道的电阻率,认为因库仑碰撞而引起的经典电阻率不足以解释放电通道的等效阻抗,应根据广义欧姆定律,充分考虑强磁场环境下特有的霍尔效应项才能更好地解释放电通道的等效阻抗。理论研究表明,在阴极等离子体温度较低(约为3 eV)时,放电通道的等离子体密度与磁场强度近似呈正比例关系,与有效电子密度近似呈反比例关系。基于“强光一号”加速器实验平台开展了单孔柱孔汇聚结构的电流传输实验,利用实验数据结合广义欧姆定律推算出放电通道的有效等离子体密度为10^(15)~10^(16) cm^(-3)。从广义欧姆定律出发,考虑强磁场对放电通道电阻率的影响,修正了电阻率估算方法,为估算单孔柱孔汇聚结构间隙短路后的损失电流提供了一个新的研究角度。本文研究结果可用于大型脉冲功率装置早期电路仿真研究以估算装置电流损失程度,为装置研制提供技术基础。

Current loss at the post-hole convolute(PHC)is an important and a difficult problem in the field of pulsed power technology.In this paper,resistivity of the discharged channel at the PHC is studied.Classical resistivity from the Coulomb collision cannot explain equivalent impedance of the discharged channel perfectly.When there is high magnetic field at the PHC,Hall effect item in the Generalized Ohm’s Law can be used to explain the equivalent impedance.Based on the effective collision electron flow steady model,the results show that the effective plasma density,the magnetic field intensity,and the voltage all can affect the resistivity of discharged channel.The results show that when the cathode plasma temperature is only about 3 eV,the resistivity is positively proportional to the magnetic field intensity and inversely proportional to the effective plasma density.According the experimental results,the effective electron density is got at the range of 10^(15)-10^(16) cm^(-3).The results can be used to estimate the equivalent impedance of the discharged channel at the PHC,and further predict the range of loss current at the PHC.