Trade-off analysis of various plasma implosion configurations for soft X-ray production of ACE 4

Summary form only given. Several possible choices for plasma radiation source loads have been compared with respect to their coupling efficiency for producing soft X-rays on the ACE 4 pulse driver. The loads evaluated are plasma implosions in the Z-pinch, theta pinch, hybrid pinch, and coaxial fast pinch configurations. The cylindrical Z-pinch is an efficient soft X-ray (SXR) radiator when driven by currents rising in about 100 ns or less. When the current rise time is longer, the Rayleigh-Taylor instability growth prevents the plasma from being compressed efficiently, and SXR emission is greatly reduced. In the case of the hybrid pinch, where the current return cage posts are spiraled around the load to produce a B/sub z/ component of the magnetic field, believed to contribute to stabilization of the Rayleigh-Taylor instability, preliminary experiments were performed on BLACKJACK 3 a few years ago, indicating better yields than a Z-pinch at the same peak current of 0.6 MA and 70 ns rise time.