Abstract Details
MODELLING OF WIRE ARRAYS ON THE Z GENERATOR AND THE EFFECTS 0F CURRENT LOSSES
Author: Christopher A Jennings
Requested Type: Oral Only
Submitted: 2009-04-21 22:03:06
Co-authors: C.A.Jennings, M. E. Cuneo, J. P. Chittenden, W.A. Stygar, B. Jones, D. J. Ampleford, E.M. Waisman, M.E. Savage, K. LeChien, D.B. Sinars
Contact Info:
Sandia National Laboratories
PO Box 5800
Albuquerque, New Mexico 87185-1
USA
Abstract Text:
Wire array Z-pinches imploded on the Z generator at Sandia National Laboratories have been used successfully for many years as a powerful compact x-ray source, as a dynamic hohlraum for radiation flow experiments, and as an intense K-shell source, while the generator has also been used extensively for isentropic compression experiments.
The success of these applications depends on the reliable coupling of the ~20MA drive current to the load, and for all configurations a significant current loss is known to occur. Our ability to model such loads largely depends on our ability to accurately represent both the generator, and these current losses, necessitating the simultaneous modeling of the load and some elements of the power feed.
Radiography of the imploding arrays has given us detailed measurements of their mass distributions, which when combined with electrical measurements and the measured x-ray pulse can be used to tightly constrain and validate simulation results. We present 3D resistive MHD simulations of wire array loads, which we couple to a four level transmission line equivalent model of the Z-generator. We demonstrate good agreement between simulation and observation for single and nested wire array loads, and describe how diagnosed and inferred current losses must be included in the circuit model to reproduce electrical measurements.
* Work supported by DOE/NNSA. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the US Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
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