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Hydrogen retention and release in first-wall coatings for tokamaks

The hydrogen retention and release of two first-wall coating materials, TiB/sub 2/ and B/sub 4/C, were measured. Hydrogen is released from TiB/sub 2/ at substantially lower temperatures or laser energy fluxes (pulsed annealing) than for B/sub 4/C. Hydrogen also diffuses to a much smaller extent into TiB/sub 2/ than into B/sub 4/C. On the basis of tritium inventory control, TiB/sub 2/ appears to be superior to B/sub 4/C.

Date: January 1, 1979

Creator: Doyle, B.L. & Vook, F.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Hydrogen depth profiling using elastic recoil detection

The elastic recoil detection (ERD) analysis technique for H profiling in the near surface regions of solids is described. ERD is shown to have the capability of detecting H and its isotopes down to concentrations of approx. 0.01 at. % with a depth resolution of a few hundred angstroms. Is is demonstrated that 2.4-MeV He ions can be used successfully to profile /sup 1/H and /sup 2/D using this technique. 12 figures.

Date: January 1, 1979

Creator: Doyle, B.L. & Peercy, P.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Low-energy beta spectroscopy using pin diodes to monitor tritium surface contamination

We show that tritium betas emitted from a surface can be counted using a pin photodiode as a solid state charged particle detector. Furthermore, we show that the range of tritium betas through air is sufficient to allow measurement of tritium on samples in air by this method. These two findings make possible a new method to survey tritium surface contamination which has advantages over existing methods. We have built and tested several prototype instruments which use this method to measure trit… more

Date: June 1, 1994

Creator: Wampler, W. R. & Doyle, B. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Simultaneous Nuclear Reaction Analysis of Boron and Phosphorus in Thin Borophosphosilicate Glass Films Using (A,P) Reactions

A method combining ({alpha},p) NRA and ellipsometry has been developed for measuring the Boron and Phosphorus content of borophosphosilicate glass (BPSG) used for interlevel dielectrics in integrated circuits. Yields from the {sup 31}P({alpha},p{sub 0}){sup 34}S (Q = 0.63 MeV) and {sup 10}B({alpha},p{sub 0}) {sup 13}C (Q = 4.06 MeV) reactions are coupled with ellipsometry thickness measurements to calculate the average atomic percent of B and P in the film. Due to the relatively low Q value of … more

Date: June 22, 1999

Creator: Walsh, D.S. & Doyle, B.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Tritium retention and removal on TFTR

Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the inject… more

Date: November 1, 1997

Creator: Mueller, D.; Blanchard, W. & Doyle, B.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Tritium retention and removal on TFTR

Date: October 1, 1997

Creator: Mueller, D.; Blanchard, W. & Doyle, B.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ion Beam Induced Charge Collection (IBICC) Studies of Cadmium Zinc Telluride (CZT) Radiation Detectors

Cadmium Zinc Telluride is an emerging material for room temperature radiation detectors. In order to optimize the performance of these detectors, it is important to determine how the electronic properties of CZT are related to the presence of impurities and defects that are introduced during the crystal growth and detector fabrication. At the Sandia microbeam facility IBICC and Time Resolved IBICC (TRIBICC) were used to image electronic properties of various CZT detectors. Two-dimensional areal… more

Date: July 22, 1999

Creator: Doyle, B.L.; Vizkelethy, G. & Walsh, D.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ion-implantation-induced phase separation and crystallization in lithia-silica glasses

Crystallization of annealed Li/sub 2/O.2SiO/sub 2/ glasses implanted with inert ions and fused SiO/sub 2/ glass implanted with Li ions was monitored using infrared reflection spectroscopy. Elastic recoil detection analysis was used to study changes in the Li and H concentration induced in these glasses by implantation and annealing. Implantation of Li/sub 2/O.2SiO/sub 2/ with inert ions results in Li depletion, accompanied by H indiffusion, in the implanted region. For Li-implanted SiO/sub 2/, … more

Date: January 1, 1980

Creator: Arnold, G. W.; Peercy, P. S. & Doyle, B. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Ion implantation applied to fusion research

Ion implantation and microanalysis have been used to investigate plasma-surface interactions relevant to fusion applications. Previous results for pure metals are reviewed and current results are presented for TiB/sub 2/ and B/sub 4/C coatings for tokamak surfaces. Enhanced trapping of implanted, low-energy hydrogen has been shown to occur at room temperature in W, Au, Pd, Mo, Nb, TiB/sub 2/, and B/sub 4/C for He or other ion predamage. Hydrogen depth profiles obtained using /sup 1/H(/sup 19/F,… more

Date: January 1, 1979

Creator: Vook, F.L.; Doyle, B.L. & Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Time-of-flight detector for heavy ion backscattering spectrometry

This report describes the results of a two-year laboratory directed research and development project to explore advanced concepts in Heavy Ion Backscattering Spectrometry (HIBS), undertaken with the goal of extending the sensitivity of this relatively new technique to levels unattainable by any other existing trace element surface analysis. Improvements in sensitivity are required for the application of HIBS to contamination control in the microelectronics industry. Tools with sensitivity appro… more

Date: April 1, 1994

Creator: Knapp, J. A.; Banks, J. C. & Doyle, B. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Quantitative Analysis with Heavy Ion E-TOF ERD

Heavy ion TOF ERD combined with energy detection (E-TOF-ERD) is a powerful analytical technique taking advantage of the following facts: the scattering cross section is usually very high ({approximately}10{sup {minus}21} cm{sup 2}/sr) compared to regular He RBS ({approximately}10{sup {minus}25} cm{sup 2}/sr), contrary to what happens with the energy resolution in ordinary surface solid barrier detectors, time resolution is almost independent of the atomic mass of the detected element, and the d… more

Date: July 23, 1999

Creator: Banks, J.C.; Doyle, B.L. & Font, A. Climent

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Time-of-flight heavy ion backscattering spectrometry

A new time-of-flight (TOF) ion detection system for Heavy Ion Backscattering Spectrometry (HIBS) is described. Examples are also given of the use of the system for measuring low-level contamination on Si wafers. Currently, the TOF-HBIS system has a sensitivity of 1 {times} 10{sup 9}/cm{sup 2} for the heaviest of surface impurity atoms and a mass resolution capable of separating Fe from Cu. The sensitivity is expected to improve by an additional order of magnitude on a industrial TOF-HIBS system… more

Date: August 1, 1993

Creator: Knapp, J. A.; Banks, J. C. & Doyle, B. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Highly focused ion beams in integrated circuit testing

The nuclear microprobe has proven to be a useful tool in radiation testing of integrated circuits. This paper reviews single event upset (SEU) and ion beam induced charge collection (IBICC) imaging techniques, with special attention to damage-dependent effects. Comparisons of IBICC measurements with three-dimensional charge transport simulations of charge collection are then presented for isolated p-channel field effect transistors under conducting and non-conducting bias conditions.

Date: December 31, 1996

Creator: Horn, K.M.; Dodd, P.E. & Doyle, B.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Saturation and isotopic replacement of deuterium in low-Z material

The saturation and replacement of hydrogen isotopes implanted into TiC, TiB/sub 2/, VB/sub 2/, B/sub 4/C, B, Si, and C has been examined experimentally and modeled theoretically. The deuterium saturation concentrations for these materials varied from .16 to .57. A new isotopic replacement model is presented which predicts isotopic trapping and exchange on the basis of the depth dependence of the implanted ions and the experimentally determined hydrogen saturation concentration. Our results indi… more

Date: January 1, 1980

Creator: Doyle, B.L.; Wampler, W.R.; Brice, D.K. & Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

He self-pumping by tokamak pump limiter materials: Al, V, Ni, and Ni/Al alloys

An ECR plasma and Colutron ion gun were used to study He self-pumping by several possible pump-limiter materials: Ni, V, Al, and Ni/Al multi-layers. Ni and V exhibited similar pumping capacities (6 {times} 10{sup 15} He/cm{sup 2}, 200 eV) whereas Al showed a reduced capacity (6 {times} 10{sup 14} He/cm{sup 2}, 200 eV) due to increased sputtering. A He retention model based upon ion implantation ranges and sputtering rates agreed with the experimental data. The pumping efficiency increased signi… more

Date: January 1, 1991

Creator: Outten, C. A.; Barbour, J. C.; Doyle, B. L. & Walsh, D. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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New technique for backscattering analysis

A new technique for analyzing Rutherford backscattering spectra is suggested. By determining the ratio of the range of a particle of energy E, to that of a particle whose energy is a fraction of E, two basic integral equations are converted into a pair of linear equations that are easy to solve and manipulate. The applicability of this formalism is demonstrated by using it to measure the stopping power of gold for alpha particles with energies 1.2, 2.2, 3.7, 5.2, and 7.1 MeV. 4 references.

Date: January 1, 1979

Creator: Keaton, P.W.; Peercy, P.S.; Doyle, B.L. & Maggiore, C.J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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H-Isotope Retention and Thermal/Ion-Induced Release in Boronized Films

Over the past decade, it has been clearly demonstrated that the composition of the very near surface ({approximately}100nm) of plasma-interactive components plays a determinant role in most processes which occur in the plasma-edge of Tokamaks. Two very successful techniques to effect control of the plasma-wall interaction are (1) in-situ deposition of amorphous carbon or boron-carbon films and (2) the use of He/C conditioning discharges or He glow discharge cleaning to modify the near surface o… more

Date: 1990

Creator: Walsh, D. S.; Doyle, B. L.; Wampler, W. R. & Hays, A. K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Retention, isotope exchange, and thermal release of hydrogen in candidate materials for TFTR

The materials studied included TiC, TiB/sub 2/, VB/sub 2/, B/sub 4/C, B, Si, graphite, and the metals Ti, V, and 304L stainless steel. The TiC and TiB/sub 2/ were formed by chemical vapor deposition on a graphite substrate. The C/Ti ratio of the TiC was measured to be 1.0 +- .05 by ion backscattering analysis. The Ti and V were explosively bonded to copper substrates, and the VB/sub 2/ was made by borodizing vanadium. Carbon (compression annealed pyrolytic graphite from Union Carbide and Papyex… more

Date: August 1, 1980

Creator: Wampler, W. R.; Doyle, B. L.; Brice, D. K. & Picraux, S. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The Sandia Ion-Electron-Optical ''Radiation Microscope''

No Description Available.

Date: September 27, 2000

Creator: Horn, K.M.; Doyle, B.L.; Walsh, D.S. & Dodd, P.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A new approach to nuclear microscopy: The ion-electron emission microscope

A new multidimensional high lateral resolution ion beam analysis technique, Ion-Electron Emission Microscopy or IEEM is described. Using MeV energy ions, IEEM is shown to be capable of Ion Beam Induced Charge Collection (IBICC) measurements in semiconductors. IEEM should also be capable of microscopically and multidimensionally mapping the surface and bulk composition of solids. As such, IIEM has nearly identical capabilities as traditional nuclear microprobe analysis, with the advantage that t… more

Date: November 1, 1998

Creator: Doyle, B.L.; Vizkelethy, G.; Walsh, D.S.; Senftinger, B. & Mellon, M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Performance of an acousto-optic Bragg cell under ion microbeam irradiation

An acousto optic (AO) deflector composed of PbMoO{sub 4} was exposed to 4 MeV protons while operating under Bragg angle conditions. An ion beam in air of 1 mm width was directed normal to the crystal face and laser beam. Between exposures, the approximately 13 mm x 8.5 mm AO deflector was mechanically translated in two dimensions in front of the fixed ion beam. The AO diffraction efficiency was mapped and was observed to change as a function of ion beam location and dose rate. These effects are… more

Date: August 1997

Creator: Paxton, A. H.; Schone, H.; Taylor, E. W.; McKinney, S. & Doyle, B. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Tritium removal by CO{sub 2} laser heating

Efficient techniques for rapid tritium removal will be necessary for ITER to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO{sub 2} or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm{sup 2} flux with an exposure time of order 10 ms is suitable to heat a 50 micron co-deposite… more

Date: October 1, 1997

Creator: Skinner, C. H.; Kugel, H.; Mueller, D.; Doyle, B. L. & Wampler, W. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Tritium Removal by CO{sub 2} Laser Heating

Efficient techniques for rapid tritium removal will be necessary for ITER (International Thermonuclear Experimental Reactor) to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO(subscript 2) or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. We have modeled the heat propagation into a surface layer and find that a multi-kW/cm(superscript2) flux with an exposure time of … more

Date: October 1, 1997

Creator: Doyle, B. L.; Skinner, C. H.; Mueller, D.; Kugel, H. & Wampler, W. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Tritium removal by CO{sub 2} laser heating

Efficient techniques for rapid tritium removal will be necessary for ITER (International Thermonuclear Experimental Reactor) to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO{sub 2} or Nd:YAG laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel. The authors have modeled the heat propagation into a surface layer and find that a multi-kW/cm{sup 2} flux with an exposure time of orde… more

Date: October 1, 1997

Creator: Skinner, C. H.; Kugel, H.; Mueller, D.; Doyle, B. L. & Wampler, W. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department