Numerical simulation of fiber and wire array Zpinches with TracII
Abstract
TracII is a two dimensional axisymmetric resistive MHD code. It simulates all three spatial components (r, z, φ) of the magnetic field and fluid velocity vectors, and the plasma is treated as a single fluid with two temperatures (T_{e},T_{i}). In addition, it can optionally include a selfconsistent external circuit. Recent modifications to the code include the addition of the 3T radiation model, a 4phase (solid liquidvaporplasma) equation of state model (QEOS), a 4 phase electrical/thermal conductivity model, and an implicit solution of poloidal (B_{z},B_{r}) magnetic field diffusion. These changes permit a detailed study of fiber and wire array Zpinches. Specifically, TracII is used to study the wire array Zpinch at the PBFAZ pulse power generator at Sandia National Laboratory. First, in 1D we examine the behavior of a single wire in the Zpinch. Then, using these results as initial radial conditions in 2D, we investigate the dynamics of wire array configurations in the rz and rθ plane. In the r z plane we examine the growth of the m = 0 or ``sausage'' instability in single wires within the array. In the rθ plane we examine the merging behavior between neighboring wires. Special emphasis is placed on trying to explain how instability growth affects the performance of the Zpinch. Lastly, we introduce TracIII, a 3D MHD code, and illustrate the m = 1 or ``kink'' instability. We also discuss how TracIII can be modified to simulate the wire array Zpinch.
 Publication:

Ph.D. Thesis
 Pub Date:
 1998
 Bibcode:
 1998PhDT.......110R
 Keywords:

 Physics: Fluid and Plasma