Symmetric aluminum-wire arrays generate high-quality Z pinches at large array radii
- Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States)
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545-0010 (United States)
- Naval Research Laboratory, Pulsed Power Physics Branch, Washington, DC 20375 (United States)
- University of New Mexico, Albuquerque, New Mexico 87131 (United States)
A Saturn-accelerator study of annular, aluminum-wire array, Z-pinch implosions, in the calculated high-wire-number plasma-shell regime [Phys. Rev. Lett. {bold 77}, 5063 (1996)], shows that the radiated x-ray pulse width increases from about 4 nsec to about 7 nsec, when the radius of the array is increased from 8.75 to 20 mm at a fixed array mass of 0.6 mg. Eulerian radiation- magnetohydrodynamic code (E-RMHC) simulations in the r-z plane suggest that this pulse-width increase with radius is due to the faster growth of the shell thickness (that arises from a two-stage development in the magnetic Rayleigh{endash}Taylor instability) relative to the increase in the shell implosion velocity. Over the array radii explored, the measured peak total x-ray power of {approximately}40 TW and energy of {approximately}325 kJ show little change outside of a {plus_minus}15{percent} shot-to-shot fluctuation and are consistent with the E-RMHC simulations. Similarly, the measured peak {ital K}-shell (lines plus continuum) power of {approximately}8 TW and energy of {approximately}70 kJ show little change with radius. The minimal change in {ital K}-shell yield is in agreement with simple {ital K}-shell radiation scaling models that assume a fixed radial compression for all initial array radii. These results suggest that the improved uniformity provided by the large number of wires in the initial array reduces the disruptive effects of the Rayleigh{endash}Taylor instability observed in small-wire-number imploding loads. {copyright} {ital 1998 American Institute of Physics.}
- OSTI ID:
- 658492
- Journal Information:
- Physics of Plasmas, Vol. 5, Issue 10; Other Information: PBD: Oct 1998
- Country of Publication:
- United States
- Language:
- English
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