12 Matching Results

Search Results

Advanced search parameters have been applied.
in subjects: "Electron Capture"  
Results: 1 - 12
open access

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
open access

Department of Li/sup /minus// and H/sup /minus// ion sources

Description: Sources of Li/sup /minus// and H/sup /minus// ions are needed for diagnostic neutral beam and for current drive in fusion plasmas. Previous efforts to generate Li/sup /minus// beams have focused on electron capture in a gas or production on a low work function surface in a plasma. Volume production of Li/sup /minus// by dissociative attachment of optically pumped lithium molecules has also been studied. This thesis presents the first experimental results for volume production of a Li/sup /minus… more
Date: December 1, 1988
Creator: Walther, S.R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Nuclear decay studies far-from-stability

Description: Nuclear decay studies far-from-stability are performed not merely to characterize new isotopes, but to establish an experimental footing for improving our theoretical understanding of nuclear structure and decay. Although progress has been made in explaining low-lying level structure for a broad range of nuclei, transition probabilities are not yet quantitatively understood. The ability to understand nuclei far-from-stability is important to astrophysics for extending r- and s-process calculati… more
Date: December 1, 1989
Creator: Firestone, R.B.; Nitschke, J.M.; Wilmarth, P.A.; Vierinen, K.S.; Chasteler, R.M.; Gilat, J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Search for resonant electron transfer and double excitation in Kr{sup 34+} + H{sub 2} collisions

Description: Resonant electron transfer and double excitation (RME) is a correlated electron process which is expected to occur in an ion-atom collision when electron capture is accompanied by the simultaneous excitation of two inner-shell electrons. RT2 is similar to resonant transfer excitation (RTE) in which only a single electron is excited. RT2E was investigated experimentally for 38--42 MeV/u Kr{sup 34} + H{sub 2} collisions by observing x-ray emission associated with single-electron capture. No event… more
Date: December 31, 1992
Creator: Zaharakis, K. E.; Haar, R. R.; Tanis, J. A.; Clark, M. W. & Plano, V. L.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Recent progress in nonperturbative electromagnetic lepton-pair production with capture in relativistic heavy-ion collisions

Description: The prospect of new colliding-beam accelerators capable of producing collisions of highly stripped high-Z ions, at fixed-target energies per nucleon up to 20 TeV or more, has motivated much interest in lepton-pair production from the QED vacuum. The time-dependent and essentially classical electromagnetic fields involved in such collisions contain larger Fourier components which give rise to sizable lepton-pair production in addition to many other exotic particles. The process of electron-posit… more
Date: December 31, 1993
Creator: Wells, J. C.; Oberacker, V. E.; Umar, A. S. & Strayer, M. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electron-phonon scattering in Si doped GaN

Description: Phonon-plasmon scattering in non-resonant Raman spectroscopy is used to determine the free electron concentration in Si doped GaN films. For various doping concentration and variable temperature the correlation with magneto-transport data is established. The freeze-out of the carrier concentration at low temperature is thus observed in a purely optical detection scheme. We observe a very long transient time of several hours for the carrier concentration as a reaction to temperature variation. T… more
Date: December 1, 1996
Creator: Wetzel, C.; Walukiewicz, W. & Ager, Joel
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A count rate based contamination control standard for electron accelerators

Description: Accelerators of sufficient energy and particle fluence can produce radioactivity as an unwanted byproduct. The radioactivity is typically imbedded in structural materials but may also be removable from surfaces. Many of these radionuclides decay by positron emission or electron capture; they often have long half lives and produce photons of low energy and yield making detection by standard devices difficult. The contamination control limit used throughout the US nuclear industry and the Departm… more
Date: December 31, 1996
Creator: May, R.T. & Schwahn, S.O.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Calculations on Electron Capture in Low Energy Ion-Molecule Collisions

Description: Recent progress on the application of a quantal, molecular-orbital, close-coupling approach to the calculation of electron capture in collisions of multiply charged ions with molecules is discussed. Preliminary results for single electron capture by N{sup 2+} with H{sub 2} are presented. Electron capture by multiply charged ions colliding with H{sub 2} is an important process in laboratory and astrophysical plasmas. It provides a recombination mechanism for multiply charged ions in x-ray ionize… more
Date: December 31, 1997
Creator: Stancil, P. C.; Zygelman, B. & Kirby, K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

State and Angular Resolved Electron Capture in a Merged-Beams Apparatus

Description: An important feature of the merged beams technique is that the heat of a reaction in the center of mass frame is kinematically amplified when transformed to the laboratory frame. A multi-grid energy analyzer is used in a merged beams apparatus to study state selective cross sections and angular distributions for electron capture between multicharged ions and atomic D at eV/u collision energies. Product D{sup +} energy spectra are measured for Si{sup 4+} + D at collision energies 3.6 eV/u to 98.… more
Date: December 31, 1997
Creator: Wu, W. & Havener, C.C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electron transfer to continuum states

Description: Gene Rudd`s analysis of doubly differential cross sections for the ionization of He atoms by proton impact suggested that electrons were being carried along by the proton for a short period of time after being ejected from the target region. Normally, this would represent an electron capture event in which an excited state of atomic hydrogen is formed. Because the electron ends up ionized it was recognized that these states of the proton must be continuum states. This insight was confirmed by o… more
Date: December 1994
Creator: Macek, J. H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Theoretical treatment of charge transfer processes of relevance to astrophysics

Description: Charge transfer is an important process in many astrophysical and atmospheric environments. While numerous experimental and theoretical studies exist for H and He targets, data on other targets, particularly metals and molecules, are sparse. Using a variety of theoretical methods and computational techniques the authors are developing methods to estimate the cross sections for electron capture (charge transfer) in slow collisions of low charge state ions with heavy (Mg, Ca, Fe, Co, Ni and Zn) n… more
Date: December 1997
Creator: Krstic, P. S.; Stancil, P. C. & Schultz, D. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
Back to Top of Screen