Numerical Analysis of a Single-Stage Fast Linear Transformer Driver Using Field-Circuit Coupled Time-Domain Finite Integration Theory

Abstract

The focus of this paper is numerical analysis on the performance of a newly designed mega-ampere (MA) class single-stage fast linear transformer driver (FLTD) with 24 separate columns in the China Z-pinch driver CZ34. However, the internal structure and media distribution of the FLTD induction cavity is very complicated and the short rise time of the bricks’ discharge current will make spatial discretization much denser, resulting in a dramatic increase in the computational complexity of a 3-D model. In this paper, the electromagnetic (EM) characteristics of the single-stage FLTD with 24-separate columns are investigated based on the time-domain finite integration theory (TD-FIT). The discharge currents of brick capacitors in the circuit model are coupled to the field model as excitations. The grid size of the key components in FLTD cavity are refined by nonuniform grids. To further reduce the number of degrees of freedom (DoFs), the surface impedance boundary condition (SIBC) is used to model good conductors. Measurements and simulation results demonstrate that TD-FIT is effective and accurate in analyzing the EM transients of FLTD. Equivalent inductance of the discharging brick will increase by ~35 nH due to the mutual flux linkage among neighboring bricks when all the 23-bricks are triggered synchronously.

Pushing the limits of existing plasma focus towards 1016 fusion neutrons with Q = 0.01

“…As an intermediate step towards a DPFQ1 project, a technologically feasible device is proposed-DPFQ0.01 to reach Q∼0.01. Linear Transformer Driver LTD technology is progressing towards efficient and reliable implementation at the MV level [32][33][34], and can be adapted for this configuration. The bank and tube parameters are given in table 2.…”