We have for several years utilized the technique of capillary wave synchronization of the break-up of single and multiple component jets to produce uniform sized liquid drops and solid particles, and hollow liquid and solid shells. The technique has also been used to encapsulate a number of liquids in impermeable spherical shells. Highly uniform glass shells have been made by generating uniform drops of glass forming materials in an aqueous solution, subsequently evaporating the water, and then fusing and blowing the remaining solids in a high temperature vertical tube furnace. Experimental results will be presented and the critical problems in further research in this field will be discussed.

We use a test particle simulation code to investigate electron cyclotron heating in a magnetic mirror well. A comparison is made between heating with one frequency and heating with two closely spaced frequencies. The code follows electron orbits in the presence of one or two monochromatic ECRH waves using guiding center equations and an equation for the electron gyrophase. Coulomb collisions with electrons and ions are simulated as a Monte Carlo scattering process. We find for the parameters of SM-1 that at the fundamental resonance the heating rate, or velocity rf diffusion coefficient, begins to decrease significantly from the quasilinear value for epsilon/sub e/ greater than or equal to 10 keV due to superadiabatic effects. As suggested by Howard et al., using multiple frequencies pushes the superadiabatic boundary to higher energies. For a given energy, the optimum frequency separations for two frequencies are those which cause the axial bounce resonances to interlace; i.e., odd multiples of the bounce frequency, ..omega../sub b/. This interlacing increases the chance of resonance overlap and thus stochasticity. If the frequency difference is equal to an even multiple of ..omega../sub b/, the diffusion coefficient returns to near its one frequency value. More generally, for more than …

The diagnostics and experimental program of a facility used to study condensed matter at high pressures are described.

Uniformity of condensed layers of DT fuel in cryogenic ICF targets is a crucial parameter in their design. Measurements by classical interferometry lacks resolution to determine DT layer uniformity for targets with thick glass shells and/or thick ablative polymer coatings. We have developed holographic interferometry as an alternative tool for layer uniformity determination. This method is sensitive only to the fuel layer itself. We describe the technique and interference pattern analysis, and present preliminary results.

The Mirror Fusion Test Facility (MFTF-B) is a large magnetic fusion energy experiment in the tandem mirror configuration. The requirement that each pair of Yin-Yang magnets, one pair at each end of the experiment, not undergo excessive lateral motion during seismic events was found to require excessively thick (> 12.7 mm) walled tubing in the support-struts, which accelerated the flow of heat inward to the 4 K magnet case from the nearby 300 K wall of the rector vessel, when any of the Cr-Ni austenite stainless steels, such as Type 304 with a 300 K yield-strength (sigma y) of 307 mpa (min.) was considered. Since the cold end of the lateral restraining strut was to be at or near 4 K, the additional constraints of good austenite stability and resistance to brittle fracture at 4 K existed. After consideration of these constraints against available information on Cr-Ni and Cr-Mn-Ni-N/sub 2/ austenitic stainless steels, grade XM-19 (Fe-22 Cr-12 Ni-5 Mn-.04 C-.02 N/sub 2/ was chosen. The mechanical properties of these welds were studied. (MOW)

The personnel neutron exposure potential at the Lawrence Livermore National Laboratory is more diverse than at many other facilities, due to the wide range of neutron producing activities. Albedo energy response problems in the face of the diversity of sources, and a concern about possible photon interferences with the neutron albedo response, have prompted development of some additional dosimetry techniques to augment the personnel monitoring program. This work now consists of two programs - the dosimeter/spectrometer (DOSPEC) in which track etch detectors are added to the albedo badge to provide some energy evaluation and gamma insensitivity, and development of solid state thin film MOS detectors to provide a real time, gamma insensitive dosimeter.

Linear-muffin-tin orbital calculations of the band structure and pressure-volume isotherms for fcc La, both at zero and finite temperatures. The calculated bulk modulus shows a rapid stiffening in the range from 40 to 50% compression, due to termination of the 6s to 5d electronic transition. When combined with a simple Slater model analysis, these results yield a temperature dependent peak in the lattice Grueneisen parameter. Experimental confirmation of this peak is found in an anomalous stiffening seen in the shock compression data for La, and it may also have some bearing on the observed saturation of the superconducting transition temperature in La around 200 kbar.