The use of ab initio molecular orbital calculations to aid in the characterization, i.e., structures and energies, of metal halide complexes present in high temperature salt vapors has been investigated. Standard LCAO-SCF methods were used and calculations were carried out using the minimal STO-3G basis set. The complexes included in this study were Al/sub 2/F/sub 6/, Al/sub 2/Cl/sub 6/, AlF/sub 3/ NH/sub 3/, AlCl/sub 3/ NH/sub 3/, and AlF/sub 3/ N/sub 2/. The Al/sub 2/X/sub 6/ complexes are found to have D/sub 2h/ symmetry in agreement with most experimental results. A planar form was found to be considerably higher in energy. The AlX/sub 3/ NH/sub 3/ complexes are found to have C/sub 3v/ symmetry with a small barrier to rotation about the Al-N axis. The AlF/sub 3/ N/sub 2/ complex is found to be weakly bound together with a binding energy of -8.2 kcal/mole at the STO-3G level.

The absolute radiative widths for E-1 and M-1 transitions in /sup 46/Sc were determined by neutron time-of-flight spectrometry. The level structure of /sup 46/Sc to 3 MeV has been studied by combining (n,..gamma..) data with previous charged particle data. As in /sup 36/Cl, scandium shows enhanced M-1's. 5 references.

The fast neutron fission cross section of /sup 233/U was measured absolutely between 0.13 and 8.0 MeV. The absolute cross section values were obtained by low geometry alpha counting and isotopic dilution analysis of various /sup 233/U samples, 2..pi..-detection of the fission fragments with an ionization chamber, and the measurement of the neutron flux with several black neutron detectors. Absolute cross sections were obtained with a 2 to 3% uncertainty over the most important energy range.

LASNEX calculations for focused laser beams on spherical targets have been performed for laser wavelengths of 0.25, 0.5, 1.0 and 2.0 microns. One-dimensional calculations, including the ponderomotive force, show a profile steepening that determines the fractional absorption by anomalous mechanism. However, increased absorption occurs at the shorter wavelengths because of more efficient inverse bremsstrahlung absorption at the higher critical densities. In general, the absorption efficiency increases with shorter laser wavelength and decreases with increasing f-number of the illuminating optics for sufficiently long plasma scale lengths. The effect of the absorption and laser wavelength on the thermal and superthermal electron physics will be discussed along with the combined effects on the implosion performance. Certain aspects of two-dimensional LASNEX calculations are presented.

We report measurements of the absolute and relative abundances, differential energy spectra, and spectral indices for cosmic-ray nuclei from Li to Fe for 2 to 150 GeV/nucleon. These measurements were made using a balloon-borne superconducting magnetic spectrometer with scintillators and optical spark chambers. The abundances of Li, Be, and B for rigidities below 10 GV/c are consistent with an energy-independent mean interstellar pathlength of 4 1/2 {+-} 1/2 g cm{sup -2} for all propagation models. The abundances of all elements above 10 GV/c are consistent with an interstellar pathlength decreasing with rigidity as R{sup -n} with an index n = 0.6{sub -0.3}{sup +0.4}. All differential source spectra can be fitted by power laws in total energy per nucleon with the same spectral index, which is between 2.5 and 2.6 depending on n. If n is near 0.5 (as for simple diffusion), the source index is 2.54 {+-} 0.03. Relative abundances at the sources are thus energy-independent, and have ratios to solar abundances as a function of first ionization potential which indicate a source temperature between 10{sup 4} and 5 x 10{sup 4} K depending on the equilibrium nature of the injection environment.

To meet the goals of the LSSA program, solar cell encapsulants must provide protection for 20 years. Consequently, the objective of the present program is to develop methodology for making confident predictions of encapsulant performance at any exposure site in the U.S.A. During the first year of the program, inherent weatherability was studied. Inherent weatherability is controlled by the three weather factors common to all exposure sites: insolation, temperature, and humidity. Emphasis was focused on the transparent encapsulant portion of miniature solar cell arrays by eliminating weathering effects on the substrate and circuitry (which are also parts of the encapsulant system). The most extensive data were for yellowing, which was measured conviently and precisely. Considerable data also were obtained on tensile strength. Changes in these two properties after outdoor exposure were predicted very well from accelerated exposure data. Although more outdoor exposure data will be received, mathematical modeling studies are continuing. This first part of the program can be said to be successfully concluded. In continuation of the inherent weatherability study, the power output of solar cells was monitored under accelerated test conditions and is being followed for outdoor exposures. For this purpose, Universal Test Specimens (UTS's) with nine different …

Successful predictions for the rate of loss of properties on outdoor exposure were made for plastic films based upon accelerated data. Degradation data for samples exposed beginning in winter, summer, or fall are discussed. The electrical performance of solar cells in Universal Test Specimens exposed outdoors is also reported. (MHR)

The accelerator-driven breeder can extend an essential energy resource, fissile fuel for nuclear reactors, by a very large factor. Symbiotic breeders could be brought on line in a shorter period of time with favorable performance predictability. The economics of using accelerator breeding of fertile-to-fissile elements will become favorable as natural fissile material becomes scarce.

This paper describes a computer-control system for a superconducting linear accelerator currently under development at Argonne National Laboratory. RSX-11M V3.1 running on a PDP 11/34 is used with CAMAC hardware to fully control 22 active beam-line elements and monitor critical accelerator conditions such as temperature, vacuum, and beam characteristics. This paper contrasts the use of an RSX compatible CAMAC driver for most CAMAC I/O operations and the use of the Connect-to-Interrupt Vector directive for fast ADC operation. The usage of table-driven software to achieve hardware configuration independence is discussed, along with the design considerations of the software interface between a human operator and a computer-control system featuring multi-function computer-readable control knobs and computer-writable displays which make up the operator's control console.

A program was conducted for the definition and demonstration of acceptable waste packages for defense transuranic waste for interim storage and terminal isolation. During FY-1977, a Contractor Questionnaire was used to gather pertinent data and to assess contractor concerns. This information was integrated into basic application data in the form of a checklist. Conceptual Container Design Specifications were developed by analyzing and evaluating the application data against Federal Regulations and interim/terminal storage constraints.

The purpose of the program is to develop an experimental/analytical evaluation of the feasibility of detecting and analyzing flaw growth in reactor pressure boundaries by means of continuously monitoring acoustic emission (AE). The investigation is devoted exclusively to ASTM Type A533, Grade B, Class 1 material. The basic approach to interpretive model development is through laboratory testing of 1 to 1/sup 1///sub 2/ inch (25.4 to 38 mm) thick fracture mechanics specimens in both fatigue and fracture at both room temperature and 550/sup 0/F (288/sup 0/C). Seven parameters are measured for each AE signal and related to fracture mechanics functions. AE data from fracture testing of 6 inch (152 mm) wall pressure vessels are also incorporated in analysis.

A 2000-ft/sup 2/ single-family residence was constructed during the second quarter of 1976 to demonstrate the energy-conserving features of additional insulation, a ventilation cooling cycle, and the Annual Cycle Energy System (ACES). The ACES is an integrated heating and cooling system that supplies space heating, hot water, and space cooling using a heat pump and low-temperature thermal storage. Included in this report are a discussion of the construction techniques employed and the problems encountered during construction, a description of the ACES concept and the ACES mechanical package, and a discussion of the ACES performance and the experiences obtained during initial operation of the ACES. Continuous operation and data collection were begun in May 1977. Performance data from November 1977 through March 1978 have shown a seasonal heating coefficient of performance of 2.77 for the ACES, giving a 63% energy reduction compared to electric resistance space and water heating.

The program for acetic acid production from marine algae has made significant progress in the current quarter. Some of the significant developments during this period are: (1) conversion of the available reducing equivalents in Chondrus crispus to organic acids has been carried to better than 80% completion; (2) thermophilic fermentations produce higher ratios of acetic acid to total acid than is the case for mesophilic fermentations (80% vs. 50%); (3) a membrane extraction process for removing organic acid products has been developed which has potential for commercial use; (4) a large scale fermentation was shown to convert over 50% of the available carbon in five days; (5) a reducing equivalents balance on the large scale fermentation was closed to with 96% of theoretical.

The simulation of geothermal reservoirs involves the solution of the equations describing multiphase, non-isothermal flow in porous media. These equations are highly nonlinear, particularly as the solution encounters the boundary of the two-phase region. There are essentially as many ways of accommodating this nonlinearity as there are numerical models of geothermal reservoirs. However, there is no universally accepted method for establishing the relative accuracy of these techniques. Well-established methodologies such as Fourier analysis and comparison against analytical solutions are simply not applicable to nonlinear systems. A necessary but not sufficient condition for convergence is the conservation of mass energy and momentum. This information is generally provided as an integral part of the numerical solution.

A suitability of 6 packing materials for removal of sodium fire aerosols in a wet cell scrubber was evaluated experimentally by measuring the efficiency and flow resistance of two 10.2 cm deep cells in series at air face velocities of 185 and 289 cm/sec, water flow rates of 0.210 ad 0.387 cm/sup 3//sec/cm/sup 2/, with and without aerosol prehumidification. The most satisfactory material was found to be 50 ..mu..m diameter stainless steel fibers at a packing density of 30 kg/m/sup 3/ (porosity = 0.99). Two 10.2 cm deep cells in series gave a removal efficiency of 85% for typical sodium fire aerosols at a face velocity of 289 cm/sec. Measurement of efficency as a function of particle size indicated a reduction in efficiency in the 0.4 to 1.1 ..mu..m size range for all packing materials.

Design of a wet cell washer and test system for air cleaning of sodium fire aerosols is described. The test aerosol was produced by continuous burning of metallic sodium in a 90 m/sup 3/ chamber to maintain a concentration of 1.14+-0.05 g/m/sup 3/ for as long as 65 minutes. The sodium fire aerosol was drawn through the wet cell washer test loop at a constant flow rate of 9 m/sup 3//min. The wet cell washer consisted of two cells in series, the first, two off-set layers of performated metal screen, and the second, a 4'' thick filter stage packed with curly glass fibers 35 ..mu..m in diameter. The wet cells were washed by solid cone water spray at 16.7 lpm at 30 psig. Sodium removal efficiencies ranged from 87 to 94%. Curly glass fibers were found to deteriorate after a six hour exposure to sodium aerosols.

Acoustic emission is attributed to energy release within a material body by localized plastic deformation or failure processes. The elastic stress waves may come from slip band formation, mechanical twinning, martensite transformation, or crack propagation. Each of these processes has slightly different acoustic characteristics allowing for easy identification. Acoustic emission was monitored during tensile tests of Type 304L austenitic stainless steel to explore the applicability of the technique to hydrogen-assisted fracture.

Acoustic emission is a transient elastic wave generated by the rapid release of energy within a material. A wide variety of mechanisms have been proposed as possible sources of acoustic emission. Proposed mechanisms have included crack propagation, precipitate fracture, twin formation, martensite formation, dislocation motion and/or multiplication. This paper is concerned with acoustic emission generated by dislocation mechanisms operating during plastic deformation. Twinning and martensitic phase transformations are excluded even though dislocation motion is involved in the nucleation and growth of twins and the growth of martensite.

In order to improve the security of handling special nuclear materials at the Oak Ridge Y-12 Plant, a sensitive acoustic emission detector has been developed that will detect forcible entry through block or tile walls, concrete floors, or concrete/steel vault walls. A small, low-powered processor was designed to convert the output from a sensitive, crystal-type acoustic transducer to an alarm relay signal for use with a supervised alarm loop. The unit may be used to detect forcible entry through concrete, steel, block, tile, and/or glass.

The sources of acoustic emission that are prevalent in brittle solids are examined, especially microcrack sources and sources that accompany macrocrack extension. The emission amplitude distributions are derived using crack opening displacement solutions pertinent to each source type, and assuming an extreme value size distribution of precursors consistent both with the functional form of typical emission amplitude distributions and with defect size observations. Acoustic emission event rates are derived from the stress and time dependence of crack growth. Stress history effects are afforded particular emphasis. Finally, some applications of acoustic emission that emerge from the analysis of the source characteristics are briefly evaluated.

Unnecessary air infiltration (''draftiness'') in buildings can be a major cause for excessive energy consumption. A method for using sound to locate, for subsequent sealing, the openings of air infiltration leakage paths in buildings has been investigated. The results of pertinent analytical studies, laboratory experiments, and field applications of this acoustic-location method are reported; and a plan is provided to encourage national implementation of the method. Low-cost, readily available equipment and procedures are described whereby the average building contractor or homeowner can use acoustic leak location to pinpoint many of the air infiltration openings in a building.

The Los Alamos Scientific Laboratory Hot Dry Rock Geothermal Energy Development Project, under the Department of Energy and in cooperation with Dresser Atlas, has conducted single- and dual-well acoustic measurements to detect fractures in the artificial geothermal reservoir at the Fenton Hill New Mexico experimental site. The measurements were made using modified Dresser Atlas logging tools. Signals traversed distances of from 48 to 150 feet between two wells. Signals intersecting hydraulic fractures in the reservoir under both hydrostatic and pressurized conditions were simultaneously detected in both wells. Upon reservoir pressurization, signals along many ray paths were severely attenuated throughout their entire coda. In addition obvious shear wave arrivals were notably absent. The signals were processed to obtain Full-Wave Acoustic, Power, and Normalized Equi-Power Logs. Analysis of these logs identified the effective ''top'' of a region of hydraulically activated fractures and fractures intersecting the injection well behind casing.

Present techniques for measuring sound velocity in liquid metals have been limited by the use of transducers which cannot survive in extreme temperature conditions. These methods also require relatively long measurement times. An optical noncontacting method has been developed which may be used for extremely short experimental times and very high temperatures and pressures. This technique is being incorporated into an isobaric expansion apparatus in which a 1 mm diam wire sample in a high pressure argon gas environment is resistively heated to melt within a time period of only a few microseconds. Before instability of the liquid column occurs, thermal expansion, enthalpy, and temperature are measured. The addition of the sound velocity measurement permits a more complete determination of the thermophysical properties of the liquid metal.

The SLSF is the largest U.S. in-reactor test vehicle for steady-state and transient experiments in an environment typical of a LMFBR core. The SLSF experiment program, sponsored by the Department of Energy, contributes to the LMFBR safety assurance program by providing data on key phenomena that occur during postulated reactor accidents. This paper describes completed SLSF experiments, in-core instrumentation used, and methods of data interpretation to determine sodium boiling and voiding dynamics. Boiling inception is shown to be identifiable from several types of in-core instruments. Location of the boiling front and void growth derived from experimental data are compared with analytical predictions. These and other data form the basis to improve understanding of accidents and to validate or guide the development of accident analysis methods.