Theoretical studies in photoelectron spectroscopy: Use of angular distribution data to deduce molecular orobital parameters. IV. Calculation of angular distributions for ejection of low‐energy photoelectrons from molecules having 1sσ2g, 2pσ2g, or 2pσ2u configurations

1975 ◽  
Vol 63 (4) ◽  
pp. 1351-1359 ◽  
Author(s):  
Burke Ritchie
Keyword(s):  
Angular Distribution ◽  
Photoelectron Spectroscopy ◽  
Low Energy ◽  
Angular Distributions ◽  
Distribution Data ◽  
Theoretical Studies

THE ANGULAR DISTRIBUTION OF PHOTOFISSION FRAGMENTS

1959 ◽  
Vol 37 (12) ◽  
pp. 1418-1437 ◽  
Author(s):  
A. P. Baerg ◽  
R. M. Bartholomew ◽  
F. Brown ◽  
L. Katz ◽  
S. B. Kowalski
Keyword(s):  
Angular Distribution ◽  
Low Energy ◽  
Photon Beam ◽  
Angular Distributions ◽  
Bremsstrahlung Energy ◽  
Isotropic Distribution ◽  
Degree Of Anisotropy ◽  
Maximum Bremsstrahlung Energy

Angular distributions of photofission fragments relative to the photon beam have been measured as a function of maximum bremsstrahlung energy in the range 6–20 Mev. The nuclides U-233, U-235, Np-237, Pu-239, and Am-241 give an isotropic distribution at all energies studied. The nuclides Th-232, U-234, U-236, U-238, and Pu-240 give anisotropic distributions which can be described by an equation of the form W(θ) = 1 + α sin2 θ where θ is the angle between fragment and beam. The degree of anisotropy is large at low energy and falls rapidly as the energy is increased. At a given energy Th-232 has the greatest degree of anisotropy and Pu-240 the least.

scholarly journals Electron Collisions with Metastable Helium

1996 ◽  
Vol 49 (2) ◽  
pp. 515 ◽  
Author(s):  
Marcus Jacka ◽  
Jennifer Kelly ◽  
Birgit Lohmann ◽  
Stephen Buckman
Keyword(s):  
Excited States ◽  
Electron Scattering ◽  
Low Energy ◽  
Angular Distributions ◽  
Theoretical Studies ◽  
Electron Collisions ◽  
Metastable Helium ◽  
First Results

Measurements and theoretical studies of electron scattering from the metastable 21,3S excited states of helium are briefly reviewed. An apparatus developed for the study of low energy differential scattering from metastable excited states is discussed in detail and the first results of angular distributions for electrons superelastically scattered from the 21,3S states at incident energies of 5, 10 and 30 eV are presented.

Positron Annihilation in Teflon and Polyethylene

1974 ◽  
Vol 52 (11) ◽  
pp. 935-939 ◽  
Author(s):  
Donald P. Kerr
Keyword(s):  
Angular Distribution ◽  
Positron Annihilation ◽  
Angular Correlation ◽  
Gamma Rays ◽  
Momentum Distribution ◽  
Angular Distributions ◽  
Distribution Data ◽  
Lifetime Component ◽  
Considerable Uncertainty ◽  
Correlation Data

Both the time spectra and the angular distributions of the annihilation gamma rays have been measured for positrons annihilating in Teflon and polyethylene in an attempt to clarify which annihilation mechanisms account for the various lifetimes in these materials. Some authors have suggested that, in addition to the longest lifetime component, one of the shorter lived components also arises from the pickoff annihilation of orthopositronium. If this were the case, substantially more positronium would be formed than is indicated by the intensity of the longest lived component alone, and should be detectable through a measurement of the intensity of the low momentum portion of the momentum distribution obtained from the angular correlation data. In the present work, four lifetimes are apparent in the time spectra although there is considerable uncertainty in resolving the two shortest components. The angular distribution data, in both cases, yielded a low momentum component whose intensity indicates that only the longest lifetime component arises from pickoff annihilation of orthopositronium. The three shorter lifetime components are discussed.

Coulomb excitation of 133Cs with protons

1985 ◽  
Vol 63 (4) ◽  
pp. 483-487 ◽  
Author(s):  
K. P. Singh ◽  
D. C. Tayal ◽  
B. K. Arora ◽  
T. S. Cheema ◽  
H. S. Hans
Keyword(s):  
Angular Distribution ◽  
Gamma Ray ◽  
Transition Probabilities ◽  
Coulomb Excitation ◽  
Spin Assignment ◽  
Thick Target ◽  
Angular Distributions ◽  
Distribution Data ◽  
Mixing Ratios ◽  
Reduced Transition Probabilities

Protons of energy 3.2–4.2 MeV have been used to Coulomb excite the states in 133Cs. The thick-target gamma-ray yields and the angular distributions were measured using a 50 cm3 Ge(Li) detector. The measurements were used to extract the reduced transition probabilities, B (E2) and B(M1), and multipole mixing ratios (δ) for the various transitions. A spin assignment has been made to the 871.8 keV level on the basis of angular distribution data. The results obtained have been compared with those of other authors.

Angular distributions of recoil products from some reactions induced in 65Cu and 197Au by protons of energy 30–85 MeV

1968 ◽  
Vol 46 (22) ◽  
pp. 3551-3563 ◽  
Author(s):  
M. K. Dewanjee ◽  
G. B. Saha ◽  
L. Yaffe
Keyword(s):  
Angular Distribution ◽  
Inelastic Scattering ◽  
Center Of Mass ◽  
Interaction Mechanism ◽  
Direct Interaction ◽  
Low Energy ◽  
Angular Distributions ◽  
Approximate Symmetry ◽  
Mass System ◽  
Model Calculations

Angular distributions of products formed in the reactions 65Cu(p,pn)64Cu, 197Au(p,pn)I96Au, and 197Au(p,p3n)194Au in the range of proton energy 30–85 MeV were studied. The angular distribution results of 64Cu and 196Au show forward peaking at low energy and sidewise peaking at higher energies. Approximate symmetry about 90° was observed for the angular distribution of 194Au in the center-of-mass system. The experimental results have been compared with (a) Monte Carlo evaporation calculations, (b) cascade–evaporation calculations at 85 MeV for 64Cu, and (c) inelastic scattering plus evaporation calculations.Good agreement was obtained with statistical theory calculations at low energy and inelastic scattering model calculations at higher energies. The comparisons indicate that the reactions proceed by the compound nucleus mechanism at lower energies and the direct interaction mechanism predominates at higher energies.

A Discussion on photoelectron spectroscopy - Angular distributions of photoelectrons and partial photoionization cross-sections

1970 ◽  
Vol 268 (1184) ◽  
pp. 141-146 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Sections ◽  
Photoelectron Spectroscopy ◽  
Ionization Potentials ◽  
Experimental Arrangement ◽  
Angular Distributions ◽  
Asymmetry Coefficient ◽  
Vibrational States ◽  
The Asymmetry

An experimental arrangement is given for measuring the angular distribution of photoelectrons. The asymmetry coefficient B is found to be 0.3 for Ar, and 0.3 and 0.12 for N2 at 584 A when the residual ion core is left in its X2z and A2II states, respectively. The partial photoionization cross-sections are given for O2 at 186, 209, 247, 330, and 460 A. New ionization potentials for O2 are found at 23.5, 24.6 and 27.3 eV ± 0.3 eV. The effects of autoionizing transitions on the population of vibrational states of N+2 are illustrated.

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