RESUMO
Nested-wire array experiments have been conducted at the 7 MA level with 150 ns implosion times from an outer diameter of 40 mm. Analysis of spectral data indicates that material from the outer array preferentially occupies the high temperature core of the stagnated pinch independent of the interwire gap in the range of 1.1 to 4.5 mm.
RESUMO
Experiments performed on the 8-MA Saturn accelerator to investigate the effects of interwire gap spacing on long-implosion-time Z pinches have resulted in the observation of a regime of optimal wire number. The experiments varied the wire number of 40 and 32 mm diam arrays, resulting in interwire gaps from 3.9 to 0.36 mm, with fixed mass and length. aluminum K-shell powers up to 3.4 TW were measured, with long, slow rising, lower power x-ray pulses for interwire gaps greater than 2.2 mm and less than 0.7 mm, and short, fast rising, higher power pulses for interwire gaps in the range 0.7-2.2 mm.
RESUMO
Maintaining plasma uniformity is an essential requirement for successful x-ray laser designs. In this work we focus on a Z-pinch-driven neonlike krypton x-ray laser design for which we (1) investigate the role of initial mass loading in affecting plasma uniformity and gain and (2) show that there are advantages in terms of plasma uniformity to diluting a krypton plasma with a low-Z material such as helium. These results are obtained by using a one-dimensional radiation hydrodynamic model. The results of this study show that low-mass 100% krypton plasmas are optimal for achieving significant gain while maintaining plasma integrity. Diluting a krypton plasma with helium has the advantage of improving plasma uniformity, but it has the disadvantages of enhanced collisionality and line broadening, which are associated with the additional free electrons.