Magnetohydrodynamic solution for a Z pinch showing the production of a hot spot

Two‐dimensional L A S N E X [National Technical Information Service Document No. DE 81026329 (Zimmerman, Report No. UCRL‐74811, 1973)] calculations are made for a Z pinch on Saturn, the low‐impedance, low‐inductance electron accelerator at the Sandia National Laboratories [D. D. Bloomquist et al. Proceedings of the Sixth IEEE Pulsed Power Conference, Arlington, VA, edited by P. J. Turchi and B. H. Bernstein (Institute of Electronics and Electrical Engineers, New York, 1987), p. 310]. The experiment is characterized by a current of 6 MA with a tungsten wire load (4 mg) at 2 mm. Two‐dimensional calculations show the evolution of the Rayleigh–Taylor instability to the bubble and spike phase, causing high‐density islands to form in the pinch opposite the bubbles. The two‐dimensional energy flow causes a ‘‘hot spot’’ to evolve, which is shown to agree in its size and brightness with pinhole camera measurements. This is the first explicit calculation of a hot spot in two dimensions employing the full magnetohydrodynamic equations.