Analysis of oxygen on and in beryllium using 2 MeV helium ions (open access)

Analysis of oxygen on and in beryllium using 2 MeV helium ions

Analysis of oxygen on beryllium can be routinely performed using helium-ion backscattering (RBS). However, determination of the bulk oxygen concentration by this technique is limited to about 350 atomic parts per million (appM). We have performed simultaneous RBS and particle-induced x-ray emission (PIXE) measurements to improve the detection limit for bulk oxygen. The RBS measurements allowed determination of the surface oxygen before and after in-situ sputter cleaning by argon ions in an ultra-high-vacuum system. PIXE measurements of specimens with surfaces maintained clean by sputtering permitted assessment of the concentration of oxygen in the bulk. For our geometry and detector sensitivities, 90% of the oxygen x-ray signal originated in the first 2.1 ..mu..m of the beryllium and a detection limit of 10 appM was found. 12 refs., 3 figs.
Date: October 2, 1986
Creator: Musket, R.G.
Object Type: Article
System: The UNT Digital Library
Recent upgrading of the modelling program COMFORT (open access)

Recent upgrading of the modelling program COMFORT

The computer code COMFORT, developed for the online control of machine functions at the SLC, has recently undergone several modifications to overcome some of its limitations. This note describes the reasons for these changes, the methods employed, some test results and the applications of the new version of the program.
Date: September 2, 1986
Creator: Hawkes, C. & Lee, M.
Object Type: Report
System: The UNT Digital Library
Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas (open access)

Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas

This report describes recent progress and plans for calendar year 1987 in the Johns Hopkins University program to develop and improve spectroscopic diagnostics for the high temperature plasmas used in magnetic fusion research. An EUV spectrograph which provides time resolved spectra along fifteen chords of a plasma device has been completed and evaluation on DIII-D will began in late 1986. Other instrumentation work includes the evaluation of a sensitive detector for ion temperature/velocity distribution determinations and a feasibility study of Zeeman polarimetry for determining magnetic fields. A comprehensive data set taken on the TEXT tokamak is undergoing analysis as a means of improving the ionic parameters used in diagnostic studies and to expand the capabilities of existing instruments. Potential new advanced in spectroscopic technology are being monitored to determine if they provide advantages for fusion research.
Date: October 2, 1986
Creator: Moos, W.
Object Type: Report
System: The UNT Digital Library
Description and application of the AERIN Code at LLNL (open access)

Description and application of the AERIN Code at LLNL

The AERIN code was written at the Lawrence Livermore National Laboratory in 1976 to compute the organ burdens and absorbed dose resulting from a chronic or acute inhalation of transuranic isotopes. The code was revised in 1982 to reflect the concepts of ICRP-30. This paper will describe the AERIN code and how it has been used at LLNL to study more than 80 cases of internal deposition and obtain estimates of internal dose. A comparison with the computed values of the committed organ dose is made with ICRP-30 values. The benefits of using the code are described. 3 refs., 3 figs., 6 tabs.
Date: January 2, 1986
Creator: King, W.C.
Object Type: Article
System: The UNT Digital Library
Recent progress with the DNA repair mutants of Chinese hamster ovary cells (open access)

Recent progress with the DNA repair mutants of Chinese hamster ovary cells

Repair deficient mutants of Chinese hamster ovary (CHO) cells are being used to identify human genes that correct the repair defects and to study mechanisms of DNA repair and mutagenesis. Five independent tertiary DNA transformants were obtained from the EM9 mutant. In these clones a human DNA sequence was identified that correlated with the resistance of the cells to CldUrd. After Eco RI digestion, Southern transfer, and hybridization of transformant DNAs with the BLUR-8 Alu family sequence, a common fragment of 25 to 30 kb was present. 37 refs., 4 figs., 3 tabs.
Date: April 2, 1986
Creator: Thompson, L.H.; Salazar, E.P.; Brookman, K.W.; Collins, C.C.; Stewart, S.A.; Busch, D.B. et al.
Object Type: Article
System: The UNT Digital Library
Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas. Progress report (open access)

Extreme ultraviolet and soft x-ray diagnostics of high-temperature plasmas. Progress report

This report describes recent progress and plans for calendar year 1987 in the Johns Hopkins University program to develop and improve spectroscopic diagnostics for the high temperature plasmas used in magnetic fusion research. An EUV spectrograph which provides time resolved spectra along fifteen chords of a plasma device has been completed and evaluation on DIII-D will began in late 1986. Other instrumentation work includes the evaluation of a sensitive detector for ion temperature/velocity distribution determinations and a feasibility study of Zeeman polarimetry for determining magnetic fields. A comprehensive data set taken on the TEXT tokamak is undergoing analysis as a means of improving the ionic parameters used in diagnostic studies and to expand the capabilities of existing instruments. Potential new advanced in spectroscopic technology are being monitored to determine if they provide advantages for fusion research.
Date: October 2, 1986
Creator: Moos, W.
Object Type: Report
System: The UNT Digital Library
Report of the Census Task Force on beamline control system requirements (open access)

Report of the Census Task Force on beamline control system requirements

A special task force was appointed to study the experience with the present beamline control system at Fermilab and to make recommendations in this area. The charge of the committee and the list of its members are appended. In order to carry out its assignment, the committee conducted a series of meetings in which it discussed the controls situation in general and the best way to approach the user community. The various groups of users were identified, and a letter was written to representatives of these groups asking questions concerning the present system and future needs. The committee met with each group to discuss the response to these questions. Written summaries of the discussions are appended. Conclusions are drawn regarding current problems, systematic upgrades and specific recommendations. (LEW)
Date: October 2, 1986
Creator: Barsotti, E. J.; Bartlett, J. F.; Bogert, V. D.; Borcherding, F. O.; Butler, J.; Czarapata, P. C. et al.
Object Type: Report
System: The UNT Digital Library
Development of high-creep-strength molybdenum and tungsten alloys by the internal nitriding process (open access)

Development of high-creep-strength molybdenum and tungsten alloys by the internal nitriding process

Substantial increases in the high-temperature creep strength of Mo-Hf alloys can be obtained by internal nitriding. The creep resistance of internally nitrided Mo-1.86 wt % Hf is more than 100 times greater than that of other commercially available molybdenum-base alloys. The HfN precipitates appear to be stable over long times at temperatures near 1600 K. Internally nitrided Mo-Hf alloys appear to be good candidates for fabrication of components of space power systems where the ratio of high-temperature strength to weight is important. They are particularly good candidates for components that can be fabricated from the lower-strength unnitrided alloy and subsequently nitrided to provide high-temperature strength.
Date: October 2, 1986
Creator: Mitchell, J. B.
Object Type: Article
System: The UNT Digital Library
The control of powerful neutral beams (open access)

The control of powerful neutral beams

While significant progress has been made in the development of neutral beams for the heating and sustaining of plasmas in large fusion experiments, the control of such devices has largely been a matter of hardware interlocks and operator experience. The need for computer-assisted control becomes more evident, however, with the initiation of multi-beamline experiments. This paper describes a software system that incorporates simple mathematical models coupled to Kalman filters for control of the high power (6 to 8 MW) beams currently under development at Lawrence Berkeley Laboratory's Neutral Beam Engineering Test Facility. Among the principal features of the system are: reduction of a large number of operator variables to just a few (usually one or two); the ability to describe most of the major neutral beams in use and under development; a foundation resting on statistical data analysis and control system principles rather than rules-of-thumb.
Date: May 2, 1986
Creator: Theil, E. & Jacobson, V.
Object Type: Report
System: The UNT Digital Library
Proposed Criterion for the Dynamic Aperture (open access)

Proposed Criterion for the Dynamic Aperture

None
Date: December 2, 1986
Creator: Parzen, G.
Object Type: Report
System: The UNT Digital Library
Gold Performance in RHIC at High Intensities (open access)

Gold Performance in RHIC at High Intensities

None
Date: November 2, 1986
Creator: Parzen, G.
Object Type: Report
System: The UNT Digital Library
Waste package performance assessment: Deterministic system model, program scope and specification (open access)

Waste package performance assessment: Deterministic system model, program scope and specification

Integrated assessments of the performance of nuclear waste package designs must be made in order to qualify waste package designs with respect to containment time and release-rate requirements. PANDORA is a computer-based model of the waste package and of the processes affecting it over the long terms, specific to conditions at the proposed Yucca Mountain, Nevada, site. The processes PANDORA models include: changes in inventories due to radioactive decay, gamma radiation dose rate in and near the package, heat transfer, mechanical behavior, groundwater contact, corrosion, waste form alteration, and radionuclide release. The model tracks the development and coupling of these processes over time. The process models are simplified ones that focus on major effects and on coupling. This report documents our conceptual model development and provides a specification for the computer program. The current model is the first in a series. Succeeding models will use guidance from results of preceding models in the PANDORA series and will incorporate results of recently completed experiments and calculations on processes affecting performance. 22 refs., 21 figs., 9 tabs.
Date: October 2, 1986
Creator: O`Connell, W. J. & Drach, R. S.
Object Type: Report
System: The UNT Digital Library
Spent-Fuel Test - Climax: An evaluation of the technical feasibility of geologic storage of spent nuclear fuel in granite: Executive summary of final results (open access)

Spent-Fuel Test - Climax: An evaluation of the technical feasibility of geologic storage of spent nuclear fuel in granite: Executive summary of final results

This summary volume outlines results that are covered in more detail in the final report of the Spent-Fuel Test - Climate project. The project was conducted between 1978 and 1983 in the granitic Climax stock at the Nevada Test Site. Results indicate that spent fuel can be safely stored for periods of years in this host medium and that nuclear waste so emplaced can be safely retrieved. We also evaluated the effects of heat and radiation (alone and in combination) on emplacement canisters and the surrounding rock mass. Storage of the spent-fuel affected the surrounding rock mass in measurable ways, but did not threaten the stability or safety of the facility at any time.
Date: September 2, 1986
Creator: Patrick, W.C.
Object Type: Report
System: The UNT Digital Library
Radiation chemical effects in experiments to study the reaction of glass in an environment of gamma-irradiated air, groundwater, and tuff (open access)

Radiation chemical effects in experiments to study the reaction of glass in an environment of gamma-irradiated air, groundwater, and tuff

The results of experiments performed by John K. Bates et al. on the reaction of nuclear waste glass with a gamma-irradiated 90{sup 0}C aqueous solution were analyzed using theory developed from past research in radiation chemistry. The aqueous solution they used is similar to what would be expected in a water-saturated environment in a nuclear waste repository in tuff. The purpose of our study was to develop an understanding of the radiation-chemical processes that occurred in the Bates et al. experiments so the results could be applied to the design and performance analysis of a proposed repository in unsaturated tuff in Nevada. For the Bates et al. experiments at the highest dose (269 Mrad), which originally contained about 16 ml of "equilibrated" water taken from Nevada Test Site Well J-13 and 5.4 ml of air, we predicted that water decomposition to H{sub 2} and O{sub 2} would produce a pressure increase of at least 1.0 MPa at 20{sup 0}C. We also predicted that nitrogen fixation from the air would occur, producing an increase of 1.6 x 10{sup -4} M in total fixed nitrogen concentration in solution. In addition, an equimolar production of H{sup +} would occur, which would be buffered …
Date: May 2, 1986
Creator: Van Konynenburg, R.A.
Object Type: Report
System: The UNT Digital Library