During this reporting period, 5 cm wide ribbons, some with no measurable residual stress, have been grown at speeds up to 5 cm/min. The relationship between residual stress and system vertical temperature gradient was further defined. The problems associated with the purity of the ribbons are being investigated. The influence of light on the recombination characteristics of defects in the ribbons has been investigated. Procedures and results are reported.

Significant progress was made during the past quarter in establishing the operability and reliability of major pieces of equipment needed for the production of protein and methane from spent sulfite liquor (SSL). Batch ozonations of SSL were conducted at times varying from 1 to 6 hours at pH's in the range of 10 to 2. These screening experiments consistently indicate that low ph's favor the breakdown of SSL into organic fragments which are more easily assimulated by micro-organisms. Approximately 23% of the organics are oxidized at all pH levels indicated that pH has no effect on the total oxidation of SSL. As was expected total sulfur content of SSL is not measurably altered by ozonation. The intense brown color of SSL is appreciably removed during ozonation. The contents of the reactor assume a light brownish-yellow hue during the course of a 4 hour ozonation treatment. Attempts to quantify the reduction have not been successful to date.

The effects of capillary die design on dopant distribution are described. A new technique for thermal geometry control utilizing inert-gas purging was implemented. Routine 38-mm-wide ribbon growth was demonstrated. 50-mm-wide ribbon growth in a length over one meter was achieved. A technology projection and guide to future silicon sheet growth was completed. (WDM)

Progress is summarized in the following task areas: ASME Boiler and Pressure Vessel Code case support, engineering and design, material development, testing, and manufacturing development. (DG)

The investigation of triphenylcyclopropenyl nickel derivatives as catalysts for the conversion of quadricyclene to norbornadiene for the thermochemical storage of solar heat was continued. It was attempted to characterize the active catalysts obtained from ((C/sub 6/H/sub 5/)/sub 3/ C/sub 3/Ni(CO)Cl)/sub 2/ and Grignara reagents, and results are presented. Also, a prototype solar collector which combines the elements of a standard solar collector which heats a ''thermal'' fluid such as water and the photochemical storage fluid is briefly described. (WHK)

Progress is reported in the following LMFBR piping design studies: collection of piping failure data, analysis of systems with prior successful operating history, and high cycle fatigue behavior of 2/sup 1///sub 4/ Cr-1 Mo steel at elevated temperature. (DG)

Some of the problems to be encountered in the large-scale use of dye lasers in an isotope separation plant are discussed. Why should dye lasers be employed. How can dye conversion efficiency be optimized. How can dye photochemical decomposition and hence running costs be minimized and how serious is this effect anyway. What are toxicity problems with the dye. These and similar issues are examined.

Inspired by new detector instrumentation that is insensitive to gamma-ray background and improved deuteron-beam bunching and sweeping of the ICT accelerator, we have measured the high-energy (2 less than E/sub n/ less than 15 MeV) neutron emission spectra from spherical targets of nitrogen, oxygen, tungsten, /sup 235/U, /sup 238/U, and /sup 239/Pu. The targets were pulsed at the center by a nominal 14-MeV neutron source at the LLL time-of-flight facility. The neutron source was obtained from the T(d,n)/sup 4/He reaction with a pulsed 400-keV deuteron beam, produced by the LLL ICT accelerator. Collimated scintillation detectors at 26/sup 0/ and 120/sup 0/ with respect to the deutron beam and at flight paths from 7.5-9.8 m recorded the neutron time-of-flight spectra.

This project involves further work on a process developed to make very thin film CdS/Cu/sub 2/S solar cells. The process is adapted to the float glass process and consists of spraying suitable chemicals on a moving ribbon of glass which floats on a bath of molten metal. The spraying produces the necessary thin films (with suitable optical and electrical properties) of SnO/sub 2/, CdS and Cu/sub 2/S. The CdS films produced are two to three microns thick, thus conserving the use of cadmium. The estimated cost per peak watt is approximately 7 cents (1975 costs) at 5 percent efficiency and an output of 37.6 x 10/sup 6/ square meters annually. The cells are blackwall cells. A float glass plant modified for the process is shown schematically. Research progress is described.

Hydrogen fusion will require a mixture of liquefied or frozen D/sub 2/ and T/sub 2/. The equilibrium constant of the mixture describes the composition of this fuel. We have calculated the equilibrium constant, K/sub DT/, for the reaction D/sub 2/ + T/sub 2/ = 2DT in the 4.2-100 K temperature range. The results agree well with previous calculations at 25, 50, and 100 K. No calculations at temperatures below 25 K have been previously published. In the 16.7 to 33.3 K temperature range, which includes the triple point, K/sub DT/ can be represented by K = 2.995 exp (-10.82/T). The values of the analogous equilibrium constants for H/sub 2/--D/sub 2/ and H/sub 2/--T/sub 2/ are also given in the 4.2 to 50 K temperature range.

In many cases, scientifically important problems cannot be well represented for visual interpretation in two dimensions. For example, in the case of potential energy surfaces, two-dimensional plots are often insufficient. Additionally, the available data in these problems tends to be rather sparse--at least by computer graphics standards. SURFACE is a computer code designed to operate with Livermore Time Sharing System hardware and software. The program's purpose is to facilitate comprehensive analysis through the generation of three-dimensional figures from sparse data sets and the production of a 16- or 35-mm movie of the surface from a wide range of perspectives. 10 figures.