Optimization of power density by decreasing the length of tungsten wire array Z pinches

Reducing the length of 30 mm diam tungsten wire arrays on the 20 MA Z pulsed power accelerator [R. B. Spielman, S. F. Breeze, C. Deeney et al., Proceedings of the 11th International Conference on Particle Beams, Prague, Czech Republic, edited by K. Junwirth and J. Ullschmied (Czech Academy of Sciences, Prague, 1996), p. 150] from 2 to 0.75 cm has shown that the radiated powers are energies that remain constant at 170+/-30 TW and 1600+/-150 kJ. The length-independent nature of the power and energy results in the radiated power per unit length increasing from 85 +/- 10 to 240+/-30 TW/cm. These high-power densities should result in approximately a 20% increase in radiation temperatures produced by a Z-pinch-driven vacuum or internal hohlarums. Two-dimensional radiation magnetohydrodynamic calculations indicate that the constant radiated energies with varying pinch lengths is consistent with the energy input being due to the work done by the Lorentz forces during the radial collapse, resulting in kinetic energy and during the on-axis pinch phase, resulting in pdV or compressional heating. (C) 1998 American Institute of Physics. [S1070-664X(98)00107-4]