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Title: Properties of {sup 112}Cd from the (n,n{sup '}{gamma}) reaction: Lifetimes and transition rates

Abstract

Lifetimes of levels below 4 MeV in {sup 112}Cd have been measured using the Doppler shift attenuation technique following inelastic scattering of monoenergetic neutrons. Reduced transition rates are determined using the results of previous studies and the current lifetimes. The electromagnetic properties of {sup 112}Cd are outlined, and together with results from previous nucleon-transfer studies and inelastic scattering, the levels in {sup 112}Cd are interpreted in terms of single-particle configurations and collective excitations, assuming a vibrational model with intruder states. The collective states and their {gamma}-ray decays are compared with IBM-2 model calculations that allow for the mixing between the normal phonon states and intruder configurations. Levels below 1.5 MeV are reproduced reasonably well, whereas at higher excitation energy the calculations fail to reproduce the data in detail.

Authors:
; ; ; ; ; ;  [1];  [2];  [3];  [4]
  1. Department of Physics, University of Guelph, Guelph, Ontario, N1G2W1 (Canada)
  2. (Switzerland)
  3. (Germany)
  4. (United States)
Publication Date:
OSTI Identifier:
20995272
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevC.75.054310; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CADMIUM 112; COLLECTIVE EXCITATIONS; COLLECTIVE MODEL; CONFIGURATION; DOPPLER EFFECT; GAMMA RADIATION; INELASTIC SCATTERING; LIFETIME; MASS NUMBER; MEV RANGE 01-10; NEUTRONS; PHONONS; VIBRATIONAL STATES

Citation Formats

Garrett, P. E., Green, K. L., Lehmann, H., Jolie, J., McGrath, C. A., Yeh, M., Yates, S. W., Institut de Physique, Universite de Fribourg, Perolles, CH-1700 Fribourg, Institut fuer Kernphysik, Universtaet zu Koeln, Zuelpicherstrasse 77, D-50937 Cologne, and Departments of Chemistry and Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055. Properties of {sup 112}Cd from the (n,n{sup '}{gamma}) reaction: Lifetimes and transition rates. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.054310.
Garrett, P. E., Green, K. L., Lehmann, H., Jolie, J., McGrath, C. A., Yeh, M., Yates, S. W., Institut de Physique, Universite de Fribourg, Perolles, CH-1700 Fribourg, Institut fuer Kernphysik, Universtaet zu Koeln, Zuelpicherstrasse 77, D-50937 Cologne, & Departments of Chemistry and Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055. Properties of {sup 112}Cd from the (n,n{sup '}{gamma}) reaction: Lifetimes and transition rates. United States. doi:10.1103/PHYSREVC.75.054310.
Garrett, P. E., Green, K. L., Lehmann, H., Jolie, J., McGrath, C. A., Yeh, M., Yates, S. W., Institut de Physique, Universite de Fribourg, Perolles, CH-1700 Fribourg, Institut fuer Kernphysik, Universtaet zu Koeln, Zuelpicherstrasse 77, D-50937 Cologne, and Departments of Chemistry and Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055. Tue . "Properties of {sup 112}Cd from the (n,n{sup '}{gamma}) reaction: Lifetimes and transition rates". United States. doi:10.1103/PHYSREVC.75.054310.
@article{osti_20995272,
title = {Properties of {sup 112}Cd from the (n,n{sup '}{gamma}) reaction: Lifetimes and transition rates},
author = {Garrett, P. E. and Green, K. L. and Lehmann, H. and Jolie, J. and McGrath, C. A. and Yeh, M. and Yates, S. W. and Institut de Physique, Universite de Fribourg, Perolles, CH-1700 Fribourg and Institut fuer Kernphysik, Universtaet zu Koeln, Zuelpicherstrasse 77, D-50937 Cologne and Departments of Chemistry and Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055},
abstractNote = {Lifetimes of levels below 4 MeV in {sup 112}Cd have been measured using the Doppler shift attenuation technique following inelastic scattering of monoenergetic neutrons. Reduced transition rates are determined using the results of previous studies and the current lifetimes. The electromagnetic properties of {sup 112}Cd are outlined, and together with results from previous nucleon-transfer studies and inelastic scattering, the levels in {sup 112}Cd are interpreted in terms of single-particle configurations and collective excitations, assuming a vibrational model with intruder states. The collective states and their {gamma}-ray decays are compared with IBM-2 model calculations that allow for the mixing between the normal phonon states and intruder configurations. Levels below 1.5 MeV are reproduced reasonably well, whereas at higher excitation energy the calculations fail to reproduce the data in detail.},
doi = {10.1103/PHYSREVC.75.054310},
journal = {Physical Review. C, Nuclear Physics},
number = 5,
volume = 75,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • Levels in {sup 112}Cd have been studied through the (n,n'{gamma}) reaction with monoenergetic neutrons. An extended set of experiments that included excitation functions, {gamma}-ray angular distributions, and {gamma}{gamma} coincidence measurements was performed. A total of 375 {gamma} rays were placed in a level scheme comprising 200 levels (of which 238 {gamma}-ray assignments and 58 levels are newly established) up to 4 MeV in excitation. No evidence to support the existence of 47 levels as suggested in previous studies was found, and these have been removed from the level scheme. From the results, a comparison of the level density is mademore » with the constant temperature and back-shifted Fermi gas models. The back-shifted Fermi gas model with the Gilbert-Cameron spin cutoff parameter provided the best overall fit. Without using the neutron resonance information and only fitting the cumulative number of low-lying levels, the level density parameters extracted are a sensitive function of the maximum energy used in the fit.« less
  • A 350 gram sample of metallic cadmium (natural mixture of isotopes) was irradiated in a reactor with slow neutrons. A total of 132 lines was separated from the gamma spectrum. The energy and intensities of the line per neutron capture are presented. A cadmium oxide target 0.8 mg cm/sup -2/ thick, enriched with 85% Cd/sup 113/, was irradiated in order to obtain the internal electron conversion spectrum from 20 to 3000 kev on a magnetic spectrometer. The lntensity, internal conversion coefficient at the K-shell alpha /sub K/, and type of transition are listed for about 25 internal conversion electron lines.more » A diagram of the gamma transition of Cd/sup 114/ is given. On averaging the gamma energies for 60 different cascades, the binding energy of the last neutron in Cd/sup 114/ was found to be 9041 plus or minus 3 kev. The density of levels increased sharply above about 2.5 Mev. Five excitation levels were found at 1.1 to 1.4 Mev. A discussion of the population of various levels, and branching of lower levels is presented. (TTT)« less