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Charge exchange processes involving iron ions

Description: A review and evaluation is given of the experimental data which are available for charge exchange processes involving iron ions and neutral H, H/sub 2/ and He. Appropriate scaling laws are presented, and their accuracy estimated for these systems. A bibliography is given of available data sources, as well as of useful data compilations and review articles. A procedure is recommended for providing single approximate formulae to the fusion community to describe total cross sections for electron c… more
Date: January 1, 1985
Creator: Phaneuf, R.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Cosmic ray half life of sup 54 Mn

Description: A search for the {beta}{sup +} decay of {sup 54}Mn has established an upper limit of 4.4 {times} 10{sup {minus}8} for this branching ratio, and a lower limit of 13.3 for the log ft value for this second forbidden unique transition. Assuming that the {beta}{sup {minus}} decay branch has the same log ft value, then its partial half life must be greater than 4 {times} 10{sup 4} years. Experiments to directly measure the {beta}{sup {minus}} decay rate of {sup 54}Mn are now in progress. 6 refs., 2 f… more
Date: August 1, 1989
Creator: Norman, E.B.; Sur, B.; Vogel, K.R.; Lesko, K.T.; Larimer, R.M. & Browne, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Production of low energy positive ions suitable for double electron capture systems

Description: Single aperture beam extraction studies have been made of a new technique to produce low divergence beams of about 0.4/sup 0/ HWHM at about 15 keV to 40 keV. Computer calculations show that this technique of coating the plasma side of the plasma grid with about 0.01'' of Al/sub 2/O/sub 3/ can also be extended to the 0.5 keV to 5 keV range with beam optics less than 1/sup 0/. Source performance including results from multiaperture source operation will be discussed.
Date: January 1, 1977
Creator: Whealton, J H; Tsai, C C; Grisham, L R & Stirling, W L
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Dynamic screening and wake effects on electronic excitation in ion-solid and ion-surface collisions

Description: The collective electronic response in a solid effectively alters ionic and atomic potentials giving rise to dynamic screening and to a wake'' of density fluctuations trailing ions as they propagate through the solid. The presence of dynamic screening modifies electronic excitation processes of projectiles in ion-solid collisions as compared to binary ion-atom collisions. We review recent theoretical and experimental studies directed at the search for and identification of signatures of dynamic … more
Date: January 1, 1991
Creator: Burgdoerfer, J. (Tennessee Univ., Knoxville, TN (United States). Dept. of Physics Oak Ridge National Lab., TN (United States))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electronegative gases

Description: Recent knowledge on electronegative gases essential for the effective control of the number densities of free electrons in electrically stressed gases is highlighted. This knowledge aided the discovery of new gas dielectrics and the tailoring of gas dielectric mixtures. The role of electron attachment in the choice of unitary gas dielectrics or electronegative components in dielectric gas mixtures, and the role of electron scattering at low energies in the choice of buffer gases for such mixtur… more
Date: January 1, 1981
Creator: Christophorou, L.G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Cosmic ray half life of sup 56 Ni

Description: A search for the {beta}{plus} decay of {sup 56}Ni has established an upper limit on the branching ratio of 7.2 {times} 10{sup {minus} 7} for the most likely such transition. This provides a lower limit of 2.3 {times} 10{sup 4} years for the cosmic ray half life of {sup 56}Ni. 2 refs., 2 figs.
Date: August 1, 1989
Creator: Norman, E.B.; Sur, B.; Lesko, K.T.; Larimer, R.M. & Browne, E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Criteria for the selection of nuclides for radioimmunotherapy

Description: This report describes many factors that need to be considered if radioimmunotherapy is to become a commonplace reality. For beta-emitting radionuclides, two physical features of importance are half-life and energy, with the latter determining the range. These features must be matched to the pharmacokinetics of the carrier and the distribution of the radionuclide, both macroscopically and microscopically. Alpha-particle emitters could be considered for cells that are readily accessible to the la… more
Date: January 1, 1986
Creator: Adelstein, S. J. & Kassis, A. I.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Atomic physics at the Argonne PII ECR (electron cyclotron resonance) Ion Source

Description: An atomic physics beam line has been set up at the Argonne PII ECR Ion Source. The source is on a 350-kV high-voltage platform which is a unique feature of particular interest in work on atomic collisions. We describe our planned experimental program which includes: measurement of state-selective electron-capture cross sections, studies of doubly-excited states, precision spectroscopy of few-electron ions, tests of quantum electrodynamics, and studies of polarization transfer using optically pu… more
Date: January 1, 1987
Creator: Dunford, R. W.; Berry, H. G.; Billquist, P. J.; Pardo, R. C.; Zabransky, B. J.; Bakke, E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Application of ECR ion source beams in atomic physics

Description: The availability of intense, high charge state ion beams from ECR ion sources has had significant impact not only on the upgrading of cyclotron and synchrotron facilities, but also on multicharged ion collision research, as evidenced by the increasing number of ECR source facilities used at least on a part time basis for atomic physics research. In this paper one such facility, located at the ORNL ECR source, and dedicated full time to the study of multicharged ion collisions, is described. Exa… more
Date: January 1, 1987
Creator: Meyer, F.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ultrarelativistic atomic collisions

Description: Calculations of the coherent production of free pairs and of pair production with electron capture from ultrarelativistic ion-ion collisions are discussed. Theory and experiment are contrasted, with some conjectures on the possibility of new phenomena. 29 refs., 5 figs., 1 tab.
Date: January 1, 1991
Creator: Bottcher, C. & Strayer, M. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electron capture in very low energy collisions of multicharged ions with H and D in merged beams

Description: An ion-atom merged-beams technique is being used to measure total absolute electron-capture cross sections for multicharged ions in collisions with H (or D) in the energy range between 0.1 and 1000 eV/amu. Comparison between experiment and theory over such a large energy range constitutes a critical test for both experiment and theory. Total capture cross-section measurements for O{sup 3+} H(D) and O{sup 5+} + H(D) are presented and compared to state selective and differential cross section cal… more
Date: January 1, 1991
Creator: Havener, C.C.; Meyer, F.W. & Phaneuf, R.A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A neutral-beam diagnostic for fast confined alpha particles in a burning plasma: Application on CIT (Compact Ignition Tokamak)

Description: Diagnostic methods for fast confined alpha particles are essential for a burning-plasma experiment. We review one- and two-electron-capture methods using energetic neutral beams, and provide quantitative estimates of signal level for a two-electron-capture method applicable to CIT. The best probe is a ground-state helium-atom beam because of its relatively good penetration into a CIT plasma and the large cross section for two-electron capture; it can be produced in useful quantities from HeH/su… more
Date: October 1, 1987
Creator: Schlachter, A. S.; Stearns, J. W. & Cooper, W. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Multiple electron capture in close ion-atom collisions

Description: Multiple electron capture is reported for Ca/sup 17 +/ in Ar. Close collisions are defined by the observation of a coincident Ca K or Ar K x-ray. A large number of electrons is transferred to the projectile in a single close collision when the Ca ion projectile is of the order of the Ar L-shell electron velocity. The cross section for electron capture is reported.
Date: October 1, 1987
Creator: Schlachter, A.S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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ELECTROCHEMISTRY OF EXCITED MOLECULES: PHOTO-ELECTROCHEMICALREACTIONS OF CHLOROPHYLLS. I

Description: Semiconductors with a sufficiently large energy gap, in contact with an electrolyte, can be used as electrodes for the study of electrochemical reactions of excited molecules. The behavior of excited chlorophyll molecules at single crystal ZnO-electrodes has been investigated. These molecules inject electrons from excited levels into the conduction band of the electrode, thus giving rise to an anodic photocurrent. The influence of various agents on this electron transfer has been studied. In th… more
Date: December 1, 1970
Creator: Tributsch, Helmut & Calvin, Melvin.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Analytical Method for the Detection of Ozone Depleting Chemicals (ODC) in Commercial Products Using a Gas Chromatograph with an Electron Capture Detector (GC-ECD)

Description: This document describes an analytical procedure that was developed for the trace level detection of residual ozone depleting chemicals (ODC) associated with the manufacture of selected commercial products. To ensure the United States meets it obligation under the Montreal Protocol, Congress enacted legislation in 1989 to impose an excise tax on electronic goods imported into the United States that were produced with banned chemicals. This procedure was developed to technically determine if resi… more
Date: August 1, 2008
Creator: Lee, Richard N.; Dockendorff, Brian P. & Wright, Bob W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Removal of nonorthogonality in the Born theory used for study of electron capture in high energy ion-atom collisions

Description: We show the complete removal of the nonorthogonality of wave functions between initial and final states in the Born theory. Hence, this treatment offers more realistic electron capture cross sections in high energy ion-atom collisions. Representative results for resonant electron capture in H/sup +/ + H collision are discussed in conjunction with other perturbative results. 10 refs., 1 fig.
Date: January 1, 1989
Creator: Kimura, M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Electron capture to the continuum from atomic hydrogen

Description: The first known measurement of the differential cross section for electron capture to the continuum(ECC) from atomic hydrogen is presented. A 12 MeV beam of C/sup 6 +/ ions traversed a static target of atomic hydrogen produced by an electron impact heated dissociation oven. The resulting ECC spectrum was obtained with a channel electron multiplier detector mounted at the exit of a 160/sup 0/ spherical sector electrostatic spectrometer with an angular acceptance of 2/sup 0/. The ECC spectrum cle… more
Date: January 1, 1984
Creator: Glass, G. A.; Engar, P.; Berry, S. D.; Breinig, M.; Deserio, R.; Elston, S. B. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Electromagnetic phenomena and collider performance at ultra-relativistic energies

Description: In this paper we discuss the two dominant electromagnetic processes that can lead to beam depletion in RHIC. The single largest nuclear depletion mechanism of the RHIC beam is estimated to be the electron capture process following pair production during beam crossing. A previous study has obtained a value of 80b per beam for Au + Au using the Weizsaecker-Williams method. However, a range of values has been advocated by other authors. A recent study has resolved this uncertainty. A more difficul… more
Date: January 1, 1989
Creator: Rhoades-Brown, M. J.; Bottcher, C. & Strayer, M. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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On the utility and ubiquity of atomic collision physics

Description: This paper is divided into three parts. In the introduction, we discuss the history and makeup of ICPEAC. In the second part, we discuss the extent of applicability of atomic collision physics. In the third part, we chose one subject (dielectronic excitation) to show the interrelationship of various sub-branches of atomic collision physics. 28 refs., 14 figs.
Date: January 1, 1989
Creator: Datz, S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Charge changing cross sections of relativistic uranium

Description: We report equilibrium charge state distributions of uranium at energies of 962 MeV/nucleon, 437 MeV/nucleon and 200 MeV/nucleon in low Z and high Z targets and the cross sections for U/sup 92 +/ reversible U/sup 91 +/ and U/sup 91 +/ reversible U/sup 90 +/ at 962 MeV/nucleon and 437 MeV/nucleon. Equilibrium thickness Cu targets produce approx. = 5% bare U/sup 92 +/ at 200 MeV/nucleon and 85% U/sup 92 +/ at 962 MeV/nucleon. 7 references, 5 figures.
Date: November 1, 1984
Creator: Gould, H.; Greiner, D.; Lindstrom, P.; Symons, T.J.M.; Crawford, H.; Thieberger, P. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Low-energy collisions of multiply charged ions with electrons, atoms and surfaces

Description: Results are presented from recent experiments at the ORNL-ECR Multicharged Ion Research Facility which have addressed low-energy interactions of multiply charged ions with electrons, hydrogen atoms and metal surfaces. The specific processes for which results are reported are electron-impact excitation, electron capture and ion neutralization. The objective of these studies is a more detailed understanding of the mechanisms which govern the interactions of multicharged ions at low (or near-thres… more
Date: January 1, 1991
Creator: Phaneuf, R. A.; Meyer, F. W.; Gregory, D. C.; Havener, C. C.; Zeijlmans van Emmichoven, P. A.; Overbury, S. H. et al.
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Partner: UNT Libraries Government Documents Department
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Electron capture from solids by positrons

Description: The capture of electrons in solids is modified from that in gasses by several factors. The most important is the collective interaction of the electrons which results in a density of electron states in the solid in wide bands. Also the high density of electrons in many solids gives a high frequency of interaction as compared to gasses, and quickly destroys any electron-positron states in the metal matrix. Consequently, most positrons implanted in a metal will rapidly thermalize, and unless they… more
Date: August 1, 1987
Creator: Howell, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Two-electron capture and loss in fast highly charged ion-atom collisions

Description: Two-electron capture and loss processes have been investigated for highly charged ions colliding with gas targets in the energy range 0.5 to 9.0 MeV/u. Ionic species used for projectiles were S(13+), Ar(15+), Ca(12-19+), and V(18-22+); target gases used were H2, He, and Ne. Double-electron capture decreases very rapidly with increasing beam energy, and the cross sections are typically 1 to 2 orders of magnitude smaller than the single-electron capture cross sections over the energy range studie… more
Date: January 1, 1986
Creator: Tanis, J. A.; Bernstein, E. M.; Clark, M. W.; Graham, W. G.; McFarland, R. H.; Morgan, T. J. et al.
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Partner: UNT Libraries Government Documents Department
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Nuclear astrophysics of supernovae

Description: In this paper, I'll give a general introduction to Supernova Theory, beginning with the presupernova evolution and ending with the later stages of the explosion. This will be distilled from a colloquium type of talk. It is necessary to have the whole supernova picture in one's mind's eye when diving into some of its nooks and crannies, as it is quite a mess of contradictory ingredients. We will have some discussion of supernova 1987a, but will keep our discussion more general. Second, we'll loo… more
Date: January 1, 1988
Creator: Cooperstein, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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