An Auger Sputter Profiling Study of Nitrogen and Oxygen Ion Implantations in Two Titiaium Alloys (open access)

An Auger Sputter Profiling Study of Nitrogen and Oxygen Ion Implantations in Two Titiaium Alloys

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.
Date: July 31, 1989
Creator: Barton, B. D.; Pope, L. E. & Wittberg, T. N.
Object Type: Report
System: The UNT Digital Library
DART: A simulation code for charged particle beams: Revision 1 (open access)

DART: A simulation code for charged particle beams: Revision 1

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.
Date: July 31, 1989
Creator: White, R.C.; Barr, W.L. & Moir, R.W.
Object Type: Report
System: The UNT Digital Library
Development of intrinsic IPT scintillator (open access)

Development of intrinsic IPT scintillator

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.
Date: July 31, 1989
Creator: Bross, A. D.
Object Type: Article
System: The UNT Digital Library
Freeze and restart of the DWPF Scale Glass Melter (open access)

Freeze and restart of the DWPF Scale Glass Melter

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.
Date: July 31, 1989
Creator: Choi, A.S.
Object Type: Report
System: The UNT Digital Library
Freeze and restart of the DWPF Scale Glass Melter (open access)

Freeze and restart of the DWPF Scale Glass Melter

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.
Date: July 31, 1989
Creator: Choi, A. S.
Object Type: Report
System: The UNT Digital Library
Grazing incidence absorption measurements. Final report (open access)

Grazing incidence absorption measurements. Final report

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.
Date: July 31, 1989
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Toxicology Studies on Lewisite and Sulfur Mustard Agents: Mutagenicity of Lewisite in the Salmonella Histidine Reversion Assay Final Report (open access)

Toxicology Studies on Lewisite and Sulfur Mustard Agents: Mutagenicity of Lewisite in the Salmonella Histidine Reversion Assay Final Report

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.
Date: July 31, 1989
Creator: Stewart, D. L.; Sass, E. J.; Fritz, L. K. & Sasser, L. B.
Object Type: Report
System: The UNT Digital Library
Toxicology Studies on Lewisite and Sulfur Mustard Agents: Mutagenicity of Sulfur Mustard in the Salmonella Histidine Reversion Assay Final Report (open access)

Toxicology Studies on Lewisite and Sulfur Mustard Agents: Mutagenicity of Sulfur Mustard in the Salmonella Histidine Reversion Assay Final Report

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).
Date: July 31, 1989
Creator: Stewart, D. L.; Sass, E. J.; Fritz, L. K. & Sasser, L. B.
Object Type: Report
System: The UNT Digital Library
Toxicology Studies on Lewisite and Sulfur Mustard Agents: Subchronic Toxicity Study of Lewisite in Rats Final Report (open access)

Toxicology Studies on Lewisite and Sulfur Mustard Agents: Subchronic Toxicity Study of Lewisite in Rats Final Report

None
Date: July 31, 1989
Creator: Sasser, L. B.; Cushing, J. A.; Kalkwarf, D. R.; Mellick, P. W. & Buschbom, R. L.
Object Type: Report
System: The UNT Digital Library
MTX (Microwave Tokamak Experiment) diagnostic and auxiliary systems for confinement, transport, and plasma physics studies (open access)

MTX (Microwave Tokamak Experiment) diagnostic and auxiliary systems for confinement, transport, and plasma physics studies

This note describes the diagnostics and auxiliary systems on the Microwave Tokamak Experiment (MTX) for confinement, transport, and other plasma physics studies. It is intended as a reference on the installed and planned hardware on the machine for those who need more familiarity with this equipment. Combined with the tokamak itself, these systems define the opportunities and capabilities for experiments in the MTX facility. We also illustrate how these instruments and equipment are to be used in carrying out the MTX Operations Plan. Near term goals for MTX are focussed on the absorption and heating by the microwave beam from the FEL, but the Plan also includes using the facility to study fundamental phenomena in the plasma, to control MHD activity, and to drive current noninductively.
Date: July 28, 1989
Creator: Hooper, E. B.; Allen, S. L.; Casper, T. A. & Thomassen, K. I.
Object Type: Report
System: The UNT Digital Library
An algorithm to calculate the beam momentum distribution from flying wire profiles (open access)

An algorithm to calculate the beam momentum distribution from flying wire profiles

Horizontal flying wire measurements give beam profiles from which information about the beam momentum distribution and betatron distribution can be extracted. When calculating these beam characteristics in the past, for the matter of simplicity, the beam has been assumed Gaussian. For beam profiles which may not be Gaussian, an algorithm to obtain the general beam momentum distribution is developed using the Fourier transform to the beam profiles. Since the profile is the convolution of the momentum distribution and the betatron distribution, using a Fourier transform method makes calculations easier. 6 figs.
Date: July 27, 1989
Creator: Wang, X.Q.
Object Type: Report
System: The UNT Digital Library
Low Temperature and Neutron Physics Studies: Final Progress Report, March 1, 1986--May 31, 1987 (open access)

Low Temperature and Neutron Physics Studies: Final Progress Report, March 1, 1986--May 31, 1987

A search for a novel coupling interaction between the Pendelloesung periodicity which is formed in a diffracting crystal and the Larmor precession of neutrons in a magnetic field has been carried out. This interaction is expected to exhibit a resonant behavior when the two spatial periodicities become matched upon scanning the magnetic field being applied to the crystal. Observations on a diffracting, perfect crystal of silicon with neutrons of wavelength 1 Angstrom show the expected resonant action but some discrepancy between the observed magnitude of the resonance effects remains for interpretation. 16 refs.
Date: July 27, 1989
Creator: Shull, C.G.
Object Type: Report
System: The UNT Digital Library
The role of the axial anomaly in determining spin-dependent parton distributions (open access)

The role of the axial anomaly in determining spin-dependent parton distributions

It is shown that the forward matrix elements of j{sub 5}{sup {mu}}, the flavor singlet axial vector current, do not measure the helicity carried by quarks and anti-quarks but also include a spin-dependent gluonic component due to the anomaly. Detailed phenomenological and field theoretic reasons are given for the necessity of a gluonic component in the matrix element of j{sub 5}{sup {mu}}. The first higher order corrections to the basic box and triangle graphs are discussed and shown not to modify the conclusions drawn in the leading order calculation. We close with a few comments on the possible phenomenological implications of the anomalous contribution. 25 refs., 6 figs.
Date: July 27, 1989
Creator: Carlitz, R.D.; Collins, J.C. & Mueller, A.H.
Object Type: Article
System: The UNT Digital Library
Determination of Fe(II)Fe(II) ratio in glass (open access)

Determination of Fe(II)Fe(II) ratio in glass

The procedure was designed for the simple, rapid determination of the Fe(II)/Fe(III) ratio in glass samples. The procedure consists of the following steps: dissolution of the pulverized glass sample in a sulfuric-hydrofluoric acid mixture, containing ammonium vanadate, which preserves the Fe(II) content; addition of boric acid to destroy iron-fluoride complexes, making the iron available for color formation with Ferrozine; addition of pH 5 buffer and Ferrozine reagent to form the magenta-colored ferrous-Ferrozine complex, with measurement of the absorbance for the determination of Fe(II) content; and, addition of ascorbic acid to reduce Fe(III) to Fe(II), with a second absorbance measurement that determines total Fe. Directions for the preparation of glass from non-radioactive sludge samples are provided. The analysis of this prepared glass for the Fe(II)/Fe(III) ratio is an indication of the ratio that would be in a plant batch of glass if made from this sludge.
Date: July 26, 1989
Creator: Baumann, E. W.
Object Type: Report
System: The UNT Digital Library
Prototype Engineered Barrier System Field Tests; Progress report (open access)

Prototype Engineered Barrier System Field Tests; Progress report

This paper presents selected preliminary results obtained during the first 54 days of the Prototype Engineered Barrier System Field Tests (PEBSFT) that are being performed in G-Tunnel within the Nevada Test Site. The test described is a precursor to the Engineered Barrier Systems Field Tests (EBSFT). The EBSFT will consist of in situ tests of the geohydrologic and geochemical environment in the near field (within a few meters) of heaters emplaced in welded tuff to simulate the thermal effects of waste packages. The PEBSFTs are being conducted to evaluate the applicability of measurement techniques, numerical models, and procedures for future investigations that will be conducted in the Exploratory Shaft Facilities of the Yucca Mountain Project (YMP). The paper discusses the evolution of hydrothermal behavior during the prototype test, including rock temperatures, changes in rock moisture content, air permeability of fractures, gas pressures, and rock mass gas-phase humidity. 10 refs., 12 figs.
Date: July 26, 1989
Creator: Ramirez, A. L.; Beatty, J.; Buscheck, T. A.; Carlson, R.; Daily, W.; LaTorre, V. R. et al.
Object Type: Article
System: The UNT Digital Library
Response to requests by FMF and DWPF concerning disposal of FMF saltstone drums in Z-Area vaults (open access)

Response to requests by FMF and DWPF concerning disposal of FMF saltstone drums in Z-Area vaults

Disposal of FMF saltstone in 55 gallon drums in the Z-Area Industrial Waste Landfill requires modification of the landfill permit. Approximately 5000 drums of FMF saltstone are currently stored on SC DHEC-permitted concrete storage pads adjacent to the burial ground. At a meeting with DWPF, FMF, and EPS on July 18, 1989, IWT agreed to supply the following information: (1) Consequence of disposal of CCA (Cu, Cr, As) treated wood pallets in the Z-Area vaults. (Four drums of FMF saltstone are currently banded to each pallet.) (2) Consequence of placing partially filled FMF drums in the Z-Area vaults. (3) Formulation for clean grout back-fill. Grout will be emplaced around and over the drums, thereby isolating them from environment (rainwater) prior to vault capping. (4) Maximum loading of FMF saltstone drums in the Z-Area vaults. (5) Consequence of void volume in drums, in clean grout, or both on groundwater modeling results. This document is a response to the above requests.
Date: July 25, 1989
Creator: Langton, C. A. & Cook, J. R.
Object Type: Report
System: The UNT Digital Library
Response to requests by FMF and DWPF concerning disposal of FMF saltstone drums in Z-Area vaults (open access)

Response to requests by FMF and DWPF concerning disposal of FMF saltstone drums in Z-Area vaults

Disposal of FMF saltstone in 55 gallon drums in the Z-Area Industrial Waste Landfill requires modification of the landfill permit. Approximately 5000 drums of FMF saltstone are currently stored on SC DHEC-permitted concrete storage pads adjacent to the burial ground. At a meeting with DWPF, FMF, and EPS on July 18, 1989, IWT agreed to supply the following information: (1) Consequence of disposal of CCA (Cu, Cr, As) treated wood pallets in the Z-Area vaults. (Four drums of FMF saltstone are currently banded to each pallet.) (2) Consequence of placing partially filled FMF drums in the Z-Area vaults. (3) Formulation for clean grout back-fill. Grout will be emplaced around and over the drums, thereby isolating them from environment (rainwater) prior to vault capping. (4) Maximum loading of FMF saltstone drums in the Z-Area vaults. (5) Consequence of void volume in drums, in clean grout, or both on groundwater modeling results. This document is a response to the above requests.
Date: July 25, 1989
Creator: Langton, C. A. & Cook, J. R.
Object Type: Report
System: The UNT Digital Library
Design and Testing of a Superfluid Liquid Helium CoolingLoop (open access)

Design and Testing of a Superfluid Liquid Helium CoolingLoop

This paper describes the design and preliminary testing of a cryogenic cooling loop that uses a thermomechanical pump to circulate superfluid liquid helium. The cooling loop test apparatus is designed to prove forced liquid helium flow concepts that will be used on the Astromag superconducting magnet facility.
Date: July 24, 1989
Creator: Gavin, L. M.; Green, M. A.; Levin, S. M.; Smoot, George F. & Witebsky, C.
Object Type: Article
System: The UNT Digital Library
Electron correlation in the continuum (open access)

Electron correlation in the continuum

We consider a class of problems, notably double ionization, which require accurate descriptions of correlation in both the initial and final states. Methods are presented for representing correlated wavefunctions on a basis spline lattice, and for calculating bound-continuum transition probabilities. 13 refs.
Date: July 24, 1989
Creator: Bottcher, C. & Strayer, M. R.
Object Type: Article
System: The UNT Digital Library
Multiple electron capture in close ion-atom collisions (open access)

Multiple electron capture in close ion-atom collisions

Collisions in which a fast highly charged ion passes within the orbit of K electron of a target gas atom are selected by emission of a K x-ray from the projectile or target. Measurement of the projectile charge state after the collision, in coincidence with the K x-ray, allows measurement of the charge-transfer probability during these close collisions. When the projectile velocity is approximately the same as that of target electrons, a large number of electrons can be transferred to the projectile in a single collision. The electron-capture probability is found to be a linear function of the number of vacancies in the projectile L shell for 47-MeV calcium ions in an Ar target. 18 refs., 9 figs.
Date: July 24, 1989
Creator: Schlachter, A. S.; Stearns, J. W.; Berkner, K. H.; Bernstein, E. M.; Clark, M. W.; DuBois, R. D. et al.
Object Type: Article
System: The UNT Digital Library
Improved bunch spreader modules (open access)

Improved bunch spreader modules

In order to raise the threshold beam current of instabilities in the fixed target run, it is required to increase the longitudinal emittance, and hence the bunch length. The bunch spreader used a noise generator through a sharp-cut ban pass filter (BPF) instead of a coherent signal. In that filter, the pass band frequency was near twice the synchrotron frequency 2f/sub s/. The bandwidth of the filter was fixed between 350Hz and 600Hz, though twice the synchrotron frequency changed from 500Hz to 300Hz after transition in Main Ring. The noise through the filter is applied to an RF amplitude modulator. In the Tevatron, where the synchrotron frequency f/sub s/ varies from 120Hz to 40Hz during acceleration, the noise is applied to a phase shifter at the frequency of f/sub s/. So, we need a tunable filter which tracks 2f/sub s/ in the Main Ring and f/sub s/ in the Tevatron. This note describes details of improved bunch spreader modules using a tunable filter used in both the Main Ring and the Tevatron. A brief description about this module along with a beam test done in the Main Ring is shown. 3 refs., 6 figs.
Date: July 20, 1989
Creator: Ieiri, Takao
Object Type: Report
System: The UNT Digital Library
Projections for a steady-state tokamak reactor based on ITER (open access)

Projections for a steady-state tokamak reactor based on ITER

The extensions of the physics and engineering guidelines for the ITER device needed for acceptable operating points for a steady-state tokamak power reactor are examined. Non-inductive current drive is provided in steady state by high-energy neutral-beam injection in the plasma core, lower-hybrid slow waves in the outer regions of the plasma and (30%) bootstrap current. Three different levels of extension of the ITER physics/engineering guide-lines, with differing assumptions on the possible plasma beta, elongation and aspect ratio, are considered for power-reactor applications. Plasma gain, Q/sub p/ = fusion power/input power, in excess of 20 and average neutron wall fluxes from 2.3 to 3.6 MW/m/sup 2/ are predicted in devices with major radii varying from 7.0 to 6.0 m and aspect ratios from 2.9 to 4. 3. Peak divertor heat fluxes range up to 12.2 MW/m/sup 2/ which is somewhat higher than the current ITER design limit of 10 MW/m/sup 2/ with a magnetically swept divertor. These designs were selected on the basis of improvements in physics/engineering consistent with time scales for development of future reactors. The design re-optimization on the basis of cost-of-electricity (COE) was then examined using a reactor systems model. This analysis generally verified the original estimates for …
Date: July 20, 1989
Creator: Devoto, R. S.; Barr, W. L.; Bulmer, R. H.; Campbell, R. B.; Fenstermacher, M. E.; Lee, J. D. et al.
Object Type: Report
System: The UNT Digital Library
Radiation measurements inside the CDF detector (open access)

Radiation measurements inside the CDF detector

During the last CDF experimental period from 6/88 to 6/1/89, radiation measurements were made inside the detector on or near the beampipe using various types of monitors. The purpose of the tests was to help predict the radiation levels for future electronics which must be located close to the interaction area. The results from two different types of monitors, PIN diodes and TLD's are reported in this paper. The TLD's (Harshaw/Filtrol type 700) are sensitive to x-rays, gammas, alphas, electrons, and protons. They are calibrated against a cesium source and corrected for nonlinear effects at higher radiation levels. The PIN diodes (Harshaw/Filtrol type DN-156) are sensitive only to neutrons. The devices are calibrated for 1 MeV neutrons and require correction factors for neutrons at other energy levels. All of the monitors were placed just outside of the VTPC, but still inside the CDF magnetic field. The monitors were located 68 inches from the center of the interaction region. The beam pipe is 2 inches in diameter. Therefore the closest monitoring points were on the beampipe or 1 inch from the beam. 5 figs., 2 tabs.
Date: July 20, 1989
Creator: Yarema, R. J.
Object Type: Report
System: The UNT Digital Library
Report from the polarization group of the Fermilab injector workshop (open access)

Report from the polarization group of the Fermilab injector workshop

The group considered physics, accelerator, and polarized source issues. Most of the physics study was concerned with what significant and unique experiments could be done if polarized protons could be accelerated in the main injector and eventually in the Tevatron. 12 refs., 4 figs.
Date: July 20, 1989
Creator: Berger, E.; Glass, G.; Imai, K.; Jones, L.; Lin, A.M.T.; Mane, S.R. et al.
Object Type: Article
System: The UNT Digital Library