Summary form only given, as follows. Numerical simulations have been carried out to investigate the performance of moderate-Z loads with higher current machines. In particular, the scaling of radiation emission with masses and velocities ranging from 0.5 mg/cm to 30 mg/cm, and from 30 cm/μs to 60 cm/μs respectively, have been considered. Such values are consistent with peak currents above 8 MA. The simulations which will be presented are focused on one-dimensional radiation hydrodynamic calculations where the risetime and peak power of the radiation pulse are considered to result primarily from the thermalization of kinetic energy at stagnation. To this end, the influence of electron-ion coupling and plasma opacity on radiative properties will be examined in detail. The importance of the two dimensional nature of the pinch and magnetic field effects will also be addressed for a small number of cases. The results of this study will be compared with recent experiments on the Z accelerator at Sandia National Laboratories where Titanium, Stainless Steel, and Copper arrays were used to look at scaling of K-shell emissions.

High temperatures generated from imploding wires arrays on the Sandia National Laboratories Z-machine produce a radiation source with a bolometric temperature of several hundred eV. By surrounding the Z-pinch implosion with a hohlraum a nearly Planckian source of about 140 eV peak temperature and 10 ns width is created. However the high temperature peak is preceded by a lower temperature foot of about 30 eV temperature lasting almost 100 ns. To prevent experiments from being destroyed by the pre-pulse a thin plastic burn-through foil is placed between the hohlraum and the experiment. The foil thickness and composition are chosen to ionize and become transparent at the time the high temperature pulse occurs. Also at these temperatures diagnostic holes in the hohlraum wall vaporize and material jets into the hole reducing the effective hole size. We present a series of Z-machine experiments which characterized and modified the raw radiation source into a suitable driver for radiation flow experiments.

Summary form only given. Pulsed power, such as the Sandia Z-machine, is contributing our understanding of where codes model reality. Fine-zoned Eulerian (and ALE) calculations, for a wide variety of geometries, show elaborate structure such as jets and instabilities, which are not calculated by Lagrangian codes. More and faster computers allow these fine-zoned (1.0 micron or less on a side) calculations to be done. The Z-machine, along with modern diagnostics, which obtain time-dependent images for more than one photon energy response, are well suited to helping us understand, in at least one case, how much of this structure is real. The geometry considered here is a CH tamped hole in a Au hohlraum for which Eulerian calculations show a jet of Au forming at a corner of the Au and moving through the CH tamping. Subsequently, large amounts of Au move into the hole. Lagrangian calculations show the Au to have only minimal motion. Here pulsed power enables us to determine the better computer model.

The Los Alamos High Energy Density Physics program uses capacitively driven low voltage, inductive-storage pulse power (including the 4.3 MJ Pegasus II capacitor bank facility) to implode cylindrical targets for hydrodynamics experiments. Once a precision driver liner was characterized an experimental series characterizing the aluminum target dynamics was performed. The target was developed for shock-induced quasi-particle ejecta experiments including holography. The concept for the liner shock experiment is that the driver liner is used to impact the target liner which then accelerates toward a collimator with a slit in it. A shock wave is set up in the target liner and as the shock emerges from the back side of the target liner, ejecta are generated. By taking a laser hologram the particle distribution of the ejecta are hoped to be determined. The goal for the second experimental series was to characterize the target dynamics and not to measure and generate the ejecta. Only the results from the third shot, Pegasus II-26 fired April 26th, 1994, from the series are discussed in detail. The second experimental series successfully characterized the target dynamics necessary to move forward towards our planned quasi-ejecta experiments.

Magnetic compression/magnetized target fusion (MAGO/MTF) is an area of fusion research that is intermediate between magnetic fusion energy (MFE) and inertial confinement fusion (ICF) in time and density scales. In this paper, the authors report the results of experiments exploring a scheme for forming a hot, magnetized plasma possibly suited for subsequent implosion in a MAGO/MTF context. The experiment described here used a copper plasma formation chamber. The outer radius of the plasma volume was 10 cm. The chamber was initially filled with 10 Torr of 50% deuterium, 50% tritium gas seeded with 0.01% neon for diagnostic purposes. The chamber behavior was computationally modeled using two-dimensional magnetohydrodynamic techniques.

Neutron source strength and yield from field-reversed configurations have been measured in the FRX-C/LSM magnetic compression experiment using plastic scintillators, indium activation samples, and moderated rhodium activation counters. The calibration of these neutron detectors is complicated by the changing shape and position of the plasma and by the presence of the massive aluminum compression coils. The overall uncertainty in the neutron measurements is estimated to be 45%.

The first evidence for runaway electrons in a spheromak plasma is presented; it is based on the observation of hard X-ray emission with an energy of about 1 MeV. The hard X-rays are produced in one or more bursts occurring early in the spheromak decay phase, after the coaxial plasma gun voltage is turned off. No obvious correlation is found between the amplitude of the hard X-ray emission and other spheromak parameters. Since there is no direct acceleration mechanism for electrons to reach MeV energy levels, these observations imply that the runaway electrons are confined for an acceleration time of greater-than-or-equal-to 20-50-mu-s and a path length of greater-than-or-equal-to 5-10 km, assuming that the electrons are accelerated in the electric field of the decaying spheromak.

Field-reversed configuration translation into a conducting cylinder that does not conserve flux is analyzed and compared to translation into a flux conserver. The differences are found to be important for the design of an adiabatic compressional heating experiment.