Investigating the influence of the wire-arrays’ electrical parameters on the load current of the z-pinch drivers

Liangping Wang,Fengju Sun,Jinhai Zhang,Aici Qiu,Mo Li

doi:10.1063/5.0008912

Abstract

Wire arrays are the typical loads which have been widely used in z-pinch research studies. When a large pulsed power accelerator is designed, the electrical parameters of the z-pinch loads including the inductance and the resistance (or the equivalent resistance) must be considered. In this paper, the inductance and the resistance of the single planar wire arrays were introduced from the experiments carried out on a Qiangguang accelerator (1.5 MA, 100 ns). The lumped-element circuit model of the wire array was established using the PSPICE software, and the model was verified by comparing the simulation results with the experimental results. The influence of the electrical parameters on the accelerator’s driving current is investigated. It shows that the inductance affects the rising edge and the peak value of the current, while the resistance mainly affects the current waveform after the stagnation of the wire array pinch load. The inductance model based on the zero-dimensional equation is compared with the inductance model based on the experimental data, and the result shows that the two different inductance models give almost the same pinch current. It can be concluded that the zero-dimensional model is valid in circuit simulation to investigate the peak current of the designed z-pinch accelerator.

Highlights

Z-pinches have been studied for many years as a plasma radiation source (PRS) with high levels of x-ray power and yield, which make them of great interest for a number of applications, including inertial confinement fusion,[1,2,3] high energy density plasmas,[4] and laboratory astrophysics.[5]
Our z-pinch experiments were carried out with single planar wire arrays, the conclusion we obtained is consistent with the analytic study about the cylindrical wire arrays on the Z facility by Whitney.[23]
The equivalent circuit for the Qiangguang accelerator including the circuit models for a planar wire array is established by the PSPICE software

Summary

INTRODUCTION

Z-pinches have been studied for many years as a plasma radiation source (PRS) with high levels of x-ray power and yield, which make them of great interest for a number of applications, including inertial confinement fusion,[1,2,3] high energy density plasmas,[4] and laboratory astrophysics.[5]. The electrical parameter of a wire-array z-pinch load includes inductance and resistance. Too many experimental results show that z-pinch loads radiate more x-ray energy than the calculated imploding kinetic energy using the zero-dimensional model;[16–18] this result implies that a time-varying inductance cannot illustrate all the electrical characteristics and an abnormal resistance or an equivalent resistance should. The influence of the wire-arrays’ electrical parameters on the design of the z-pinch drivers is studied.

INDUCTANCE AND RESISTANCE OF A PLANAR WIRE ARRAY

CIRCUIT MODELS FOR THE RESISTANCE AND INDUCTANCE OF A WIRE ARRAY

INFLUNCE OF THE ELETRIC PARAMETERS ON THE ACCELERAOTR CURRENT

Findings

CONCLUSION