In analyzing CaF/sub 2/:Dy (TLD-200) data from the environmental monitoring program at the Lawrence Livermore Laboratory, a quantity of significance is the dose to the thermoluminescence dosimeters during shielded storage. This paper describes a method for determining this shield dose, which can then be related to the dose from cosmic radiation. Data, based on quarterly TLD exposure periods, show a range of 43-56 ..mu..rads per day in a 75 mm thick lead shield. Observed variations in the shield dose have led to studies of prolonged exposure of TLDs to elevated and reduced temperatures typical of those in the Livermore Valley.

The objective of this research program is to investigate the technical and economic feasibility of producing solar-cell-quality sheet silicon by dip-coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon. The dip-coating methods studied were directed toward a minimum-cost process with the ultimate objective of producing solar cells with a conversion efficiency of 10 percent or greater. The technique shows excellent promise for low-cost, labor-saving, scale-up potentialities and would provide an end product of sheet silicon with a rigid and strong supportive backing. An experimental dip-coating facility was designed and constructed, and, using this facility, several substrates have been successfully dip-coated with areas as large as 25 cm/sup 2/ and thicknesses of 12 ..mu..m to 250 ..mu..m. There appears to be no serious limitation on the area of a substrate that could be coated. Of the various substrate materials dip-coated this reporting period, mullite appears, at this time, to best satisfy the requirement of this research program. An inexpensive process has been developed for producing mullite in the desired geometry, thus satisfying the cost objectives of the program.

The objective of this research program is to investigate the technical and economic feasibility of producing solar-cell quality sheet silicon by dip-coating one surface of carbonized ceramic substrates with a thin layer of large-grain polycrystalline silicon. Of the various substrate materials dip-coated this reporting period, mullite appears, at this time, to best satisfy the requirements of this research program. Dip-coating experiments continue to demonstrate that layer thickness and grain size are dependent on and can be controlled by pulling rate and melt temperature. Crystalline grains as large as 1 mm wide and 2 cm or more long can consistently be grown in layers 35 to 50 ..mu.. meters thick. (WDM)

Vehicle propulsion concepts utilizing flywheel energy are described. Analyses are presented for sizing an inductor motor/alternator/flywheel for application to a 3000 pound vehicle. Component tradeoffs are included for the inductor motor/alternator drive, the solid state inverter/rectifier, the control circuit, and a composite flywheel. Design specifications for the machine are established and a test plan defined.

Molecular beam techniques were used to study the reactive and non-reactive scattering of the nitrogen positive ion from hydrogen isotopes and helium, at energies above the stability limit for spectator stripping. Reactive scattering was observed from H/sub 2/ and HD targets. Non-reactive scattering was observed from H/sub 2/ and D/sub 2/ targets, and from He at one energy. A correlation diagram for the system is presented and compared with the available a priori calculations. Two surfaces are expected to lead to reaction. One is a /sup 3/A/sub 2/ - /sup 3/PI surface, the other, a /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface. Collinear approaches are expected to be most reactive on the /sup 3/B/sub 1/ - /sup 3/..sigma../sup -/ surface; noncollinear, on the /sup 3/A/sub 1/ - /sup 3/PI surface. Theoretical models are presented in which an incident hard sphere A, representing the projectile ion, strikes one of a pair of hard spheres B-C representing the B hydrogen molecule. After an impulsive A-B collision, an impulsive B-C collision may take place. The relative energy of A to B is then examined, and a reactive event is considered to have occurred if the energy is less than the dissociation energy …

A method for calculating quasi-one-dimensional, steady-state, two-phase dispersed droplet-in-vapor flow has been developed. The technique is applicable to both subsonic and supersonic single component flow in which normal shock waves may occur, and is the basis for a two-dimensional model. The flow is assumed to be inviscid except for droplet drag. Temperature and pressure equilibrium between phases is assumed, although this is not a requirement of the technique. Example calculations of flow in one-dimensional nozzles with and without normal shocks are given and compared with experimentally measured pressure profiles for both low quality and high quality two-phase steam/water flow.

A review of laser-compression experiments is given. Diagrams illustrating various compression data are described. (MOW)

Solid-state electrochemical methods are being used to determine structural, thermodynamic, and transport properties in materials pertinent to the fluorination of metals at elevated temperatures. The solubility and diffusivity of fluorine in solid metals (initially nickel) are being studied by a potentiostatic electrochemical procedure by which changes in an impressed cell voltage induces changes in the activity of fluorine at a metal/electrolyte interface while the recording of the resulting cell current as a function of time can be interpreted to yield the desired quantities. Defect structures in metal fluoride compounds (initially NiF/sub 2/ and PbF/sub 2/) are being studied through measurements and interpretation of the electrical conductivity. The variation in the conductivities of the pure and impurity-doped compound as a function of fluorine activity can be interpreted to establish the partial ionic and electronic conductivities of the compounds, and the concentrations and mobilities of the carriers. Finally, a CaF/sub 2/-electrolyte probe (gauge) is being developed for the measurement of fluorine activities in gases at elevated temperatures. The literature has been searched and studied. Experimental materials have been ordered and two high-temperature electrochemical systems have been constructed and tested. The electrical instrumentation has been tested and calibrated. A porous graphite electrode was …