The CHROMA laser facility at KMS Fusion has been used to irradiate a variety of microdot targets. These include aluminum dots and mixed bromine dots doped with K-shell (magnesium) emitters. Simultaneously time- and space-resolved K-shell and L-shell spectra have been measured and compared to dynamic model predictions. The electron density profiles are measured using holographic interferometry. Temperatures, densities, and ionization distributions are determined using K-shell and L-shell spectral techniques. Time and spatial gradients are resolved simultaneously using three diagnostics: a framing crystal x-ray spectrometer, an x-ray streaked crystal spectrometer with a spatial imaging slit, and a 4-frame holographic interferometer. Significant differences have been found between the interferometric and the model-dependent spectral measurements of plasma density. Predictions by new non-stationary L-shell models currently being developed are also presented. 14 refs., 10 figs.

The current situation concerning supernova simulations and the theory of neutron star structure are studied with respect to what they tell about the equation of state. A new mechanism that could help power supernovae is suggested.

Fermilab plans to increase the energy of its H/sup /minus// linac from 200 to 400 MeV as part of a program to enhance the operation of the Tevatron for both collider and fixed target operation. The principal motivation for the linac upgrade is to reduce the incoherent spacecharge tuneshift at injection into the booster synchrotron. Other parts of the program are required to fully exploit the linac upgrade, but immediate improvement should be seen in booster performance with consequent benefit for collider luminosity and probably fixed target intensity as well. Improved diagnostic and beam steering capabilities and the elimination of some of the obsolete triode power amplifiers are expected to lead to improved reliability and consistency in linac operation. The grade design has been presented in a conceptual design report. This paper treats the current evolution of the general design and principal parameters of the linac with little reference to components, supporting systems, conventional facilities, etc. 13 refs., 5 figs., 1 tab.

A distributed data acquisition system that uses various computer hardware and software is being developed to support magnetic fusion experiments at Lawrence Livermore National Laboratory (LLNL). The experimental sequence of operations is controlled by a supervisory program, which coordinates software running on Digital Equipment Corporation (DEC) VAX computers, Hewlett-Packard (HP) UNIX-based workstations, and HP BASIC desktop computers. An interprocess communication system (IPCS) allows programs to communicate with one another in a standard manner regardless of program location in the network or of operating system and hardware differences. We discuss the design and implementation of this data acquisition system with particular emphasis on the coordination model and the IPCS. 5 refs., 3 figs.

Compact x-ray lasers in the laboratory can be produced with ultrahigh gradient rf linacs based on recent advances in linac technology by an SLAC-LLNL-LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be converted to soft x rays in the range of 2--10 nm by passage through short period, high field strength wigglers. Alternatively, the beam can pump a low density dielectric to produce x rays via recombination. Such linear light sources can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 15 refs., 7 figs., 3 tabs.

The Linac Upgrade program, a portion of the Tevatron Upgrade, calls for increasing the energy of the existing 200 MeV, 201.25 MHz linac to 400 MeV in order to reduce beam emittance degradation in the Booster. This is to be accomplished by replacing the last four Alvarez linac tanks with more efficient, higher gradient 805 MHz linac structure. One of the linac structures currently under study in a collaboration between Fermilab and SAIC is the Disk-and-Washer accelerating structure with bi-periodic tee supports, four per washer pair. This structure has a stop-band for the TM/sub 11/ mode (a problem in other designs) centered near the ..pi.. TM/sub 02/ accelerating mode frequency. A novel heat shrinking technique is used in the construction of a ten-cell one-meter long vacuum prototype structure. Description of the structure, testing techniques and test results are presented. 9 refs., 4 figs., 1 tab.