This paper presents a recently modified version of the 2-D code, DART, which can simulate the behavior of a beam of charged particles whose trajectories are determined by electric and magnetic fields. This code was originally used to design laboratory-scale and full-scale beam direct converters. Since then, its utility has been expanded to allow more general applications. The simulation includes space charge, secondary electrons, and the ionization of neutral gas. A beam can contain up to nine superimposed beamlets of different energy and species. The calculation of energy conversion efficiency and the method of specifying the electrode geometry are described. Basic procedures for using the code are given, and sample input and output fields are shown. 7 refs., 18 figs.

After over two years of successful demonstration of many design and operating concepts of the DWPF Melter system, the last Scale Glass Melter campaign was initiated on 6/9/88 and consisted of two parts; (1) simulation of noble metal buildup and (2) freeze and subsequent restart of the melter under various scenarios. The objectives were to simulate a prolonged power loss to major heating elements and to examine the characteristics of transient melter operations during a startup with a limited supply of lid heat. Experimental results indicate that in case of a total power loss to the lower electrodes such as due to noble metal deposition, spinel crystals will begin to form in the SRL 165 composite waste glass pool in 24 hours. The total lid heater power required to initiate joule heating was the same as that during slurry-feeding. Results of a radiative heat transfer analysis in the plenum indicate that under the identical operating conditions, the startup capabilities of the SGM and the DWPF Melter are quite similar, despite a greater lid heater to melt surface area ratio in the DWPF Melter.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Validity of rules issued by the Texas Board of Health to implement the Texas Abortion Facility Reporting and Licensing Act, article 4512.8, V.T.C.S. (RQ-1511)

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Liability of a municipality for acts of employees of a public health district of which the city is a member (RQ-1555)

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Samples of two titanium alloys, Ti-6A1-4V and Ti-15V-3Cr-3Sn-3A1, were ion implanted with a combination of nitrogen (N+) and oxygen (O+). For each alloy, implantation parameters were chosen to give implanted nitrogen concentrations of approximately 10 or 50 atomic percent, from a depth of 100 nanometers to a depth of 400 nanometers. In all but one case, dual energy (200 keV and 90 keV) implantations of nitrogen were used to give a relatively uniform nitrogen concentration to a depth of 300 nanometers. In each case, oxygen was implanted at 35 keV, following the nitrogen implantation, to give an oxygen-enriched region near the surface. The implanted samples were then examined by Auger electron spectroscopy (AES) combined with argon ion sputtering. In order to determine the stoichiometry of the nitrogen implanted regions, it was necessary to determine the N (KVV) contribution to the overlapping N (KVV) and Ti (LMM) Auger transitions. It was also necessary to correct for the ion-bombardment-induced compositional changes which have been described in an earlier study of titanium nitride thin films. The corrected AES depth profiles were in good agreement with theoretical predictions.

The mutagenic potential of bis 2-chloroethyl sulfide (HD} a bifunctional sulfur mustard was evaluated in the standard plate incorporation version and the preincubation modification of the Salmonella/microsomal assay with tester strains TA97, TA98, TA100 and TA102, with and without 59 activation. HD-induced point mutations in strain TA102 and frameshift mutations in TA97 but showed little or no mutagenicity against strains TA98 and TA100. Extensive HD-induced cell killing was observed with the excision repair deficient strains (TA100, TA98 and TA97) but not with strain TA102, which is wild-activation by Aroc1or induced rat liver microsomes (S9).

The mutagenic potential of lewisite was evaluated in the standard plate incorporation method and by the preincubation modification of the Ames Salmonella/microsomal assay with tester strains TA97, TA98, TAlOO and TA102. All strains were tested with activation (20 and 50 {micro}l/ plate) and without activation. The lewisite was screened initially for toxicity with TA98 over a range of concentrations from 0.01 to 250 {micro}g of material per plate. However, concentrations selected for mutagenicity testing were adjusted to a range of 0.001 to 5 {micro}g/plate because of the sensitivity of tester strain TA102, which exhibited cytotoxicity at 0.01 ug/plate. No mutagenic response was exhibited by any of the strains in either method used. All other tester strains showed evidence of cytoxicity (reduction in mutagen response or sparse background lawn) at 5.0 {micro}g/plate or lower.

We report on the development of a new polystyrene based plastic scintillator. Optical absorption, fluorescence and light output measurements are presented. Preliminary results of radiation damage effects are also given and compared to the effects on a commercial plastic scintillator, NE 110. 6 refs., 12 figs.

This final report summarizes the results of a series of different measurements to characterize various mirrors of interest to Los Alamos National Laboratory and the Boeing Aerospace free electron laser program. Most of the measurements were of the glancing incidence characteristics of different overcoated silver mirrors. These included the absolute absorptance as a function of angle of incidence (0--88{degrees}), laser wavelength (0.5145 and 1.06 {mu}m), polarization, and exposure to room air. The latter measurement examined the ability of the overcoated silver mirrors to resist tarnishing. Overcoating materials used were single-layer ThF{sub 4} and MgF{sub 2}, a very thin layer of Al{sub 2}O{sub 3}, and diamond. As a result of the work performed during this program, significant progress has been made to find a better alternative to bare silver mirrors for high-power laser applications. Thick dielectric overcoats do protect the silver mirrors from tarnishing, but problems associated with accurately controlling the optical constants of the dielectric during the coating process appear to make it difficult to achieve the desired optical properties of the mirrors at high angles of incidence.

After over two years of successful demonstration of many design and operating concepts of the DWPF Melter system, the last Scale Glass Melter campaign was initiated on 6/9/88 and consisted of two parts; (1) simulation of noble metal buildup and (2) freeze and subsequent restart of the melter under various scenarios. The objectives were to simulate a prolonged power loss to major heating elements and to examine the characteristics of transient melter operations during a startup with a limited supply of lid heat. Experimental results indicate that in case of a total power loss to the lower electrodes such as due to noble metal deposition, spinel crystals will begin to form in the SRL 165 composite waste glass pool in 24 hours. The total lid heater power required to initiate joule heating was the same as that during slurry-feeding. Results of a radiative heat transfer analysis in the plenum indicate that under the identical operating conditions, the startup capabilities of the SGM and the DWPF Melter are quite similar, despite a greater lid heater to melt surface area ratio in the DWPF Melter.