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Title: Discovery of low-lying E1 and M1 strengths in {sup 232}Th

Abstract

Properties of low-energy dipole states in {sup 232}Th have been investigated with the nuclear resonance fluorescence technique. The present work used monoenergetic {gamma}-ray beams at energies of 2-4 MeV from the high-intensity {gamma}-ray source at Triangle Universities Nuclear Laboratory. Over 40 transitions corresponding to deexcitation to the ground state and first excited state were observed for the first time. Excitation energies, integrated cross sections, decay widths, branching ratios, and transition strengths for those states in {sup 232}Th were determined and compared with quasiparticle random-phase-approximation calculations. A large number of E1 transitions were observed for the first time in actinide nuclei with summed strength of 3.28(69)x10{sup -3} e{sup 2} fm{sup 2}. The observed summed M1 strength of 4.26(63){mu}{sub N}{sup 2} is in good agreement with the other actinides and with the systematics of the scissors mode in deformed rare-earth nuclei.

Authors:
; ; ;  [1];  [2]; ;  [3];  [3]
  1. Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States)
  2. Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)
  3. Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)
Publication Date:
OSTI Identifier:
21499509
Resource Type:
Journal Article
Journal Name:
Physical Review. C, Nuclear Physics
Additional Journal Information:
Journal Volume: 83; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevC.83.034615; (c) 2011 American Institute of Physics; Journal ID: ISSN 0556-2813
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ACTINIDES; BRANCHING RATIO; CROSS SECTIONS; DE-EXCITATION; DIPOLES; E1-TRANSITIONS; EXCITATION; GAMMA RADIATION; GAMMA SOURCES; M1-TRANSITIONS; MEV RANGE 01-10; NUCLEAR DECAY; RANDOM PHASE APPROXIMATION; RARE EARTH NUCLEI; RESONANCE FLUORESCENCE; THORIUM 232; ACTINIDE NUCLEI; ALPHA DECAY RADIOISOTOPES; APPROXIMATIONS; CALCULATION METHODS; DECAY; DIMENSIONLESS NUMBERS; ELECTROMAGNETIC RADIATION; ELEMENTS; EMISSION; ENERGY RANGE; ENERGY-LEVEL TRANSITIONS; EVEN-EVEN NUCLEI; FLUORESCENCE; HEAVY NUCLEI; INTERMEDIATE MASS NUCLEI; IONIZING RADIATIONS; ISOTOPES; LUMINESCENCE; METALS; MEV RANGE; MULTIPOLE TRANSITIONS; MULTIPOLES; NUCLEI; PHOTON EMISSION; RADIATION SOURCES; RADIATIONS; RADIOISOTOPES; SPONTANEOUS FISSION RADIOISOTOPES; THORIUM ISOTOPES; YEARS LIVING RADIOISOTOPES

Citation Formats

Adekola, A S, Hammond, S L, Hill, A, Karwowski, H J, Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, Angell, C T, Howell, C R, Kwan, E, Department of Physics, Duke University, Durham, North Carolina 27708, Kelley, J H, and Department of Physics, North Carolina State University, Raleigh, North Carolina 27695. Discovery of low-lying E1 and M1 strengths in {sup 232}Th. United States: N. p., 2011. Web. doi:10.1103/PHYSREVC.83.034615.
Adekola, A S, Hammond, S L, Hill, A, Karwowski, H J, Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, Angell, C T, Howell, C R, Kwan, E, Department of Physics, Duke University, Durham, North Carolina 27708, Kelley, J H, & Department of Physics, North Carolina State University, Raleigh, North Carolina 27695. Discovery of low-lying E1 and M1 strengths in {sup 232}Th. United States. https://doi.org/10.1103/PHYSREVC.83.034615
Adekola, A S, Hammond, S L, Hill, A, Karwowski, H J, Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, Angell, C T, Howell, C R, Kwan, E, Department of Physics, Duke University, Durham, North Carolina 27708, Kelley, J H, and Department of Physics, North Carolina State University, Raleigh, North Carolina 27695. 2011. "Discovery of low-lying E1 and M1 strengths in {sup 232}Th". United States. https://doi.org/10.1103/PHYSREVC.83.034615.
@article{osti_21499509,
title = {Discovery of low-lying E1 and M1 strengths in {sup 232}Th},
author = {Adekola, A S and Hammond, S L and Hill, A and Karwowski, H J and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 and Angell, C T and Howell, C R and Kwan, E and Department of Physics, Duke University, Durham, North Carolina 27708 and Kelley, J H and Department of Physics, North Carolina State University, Raleigh, North Carolina 27695},
abstractNote = {Properties of low-energy dipole states in {sup 232}Th have been investigated with the nuclear resonance fluorescence technique. The present work used monoenergetic {gamma}-ray beams at energies of 2-4 MeV from the high-intensity {gamma}-ray source at Triangle Universities Nuclear Laboratory. Over 40 transitions corresponding to deexcitation to the ground state and first excited state were observed for the first time. Excitation energies, integrated cross sections, decay widths, branching ratios, and transition strengths for those states in {sup 232}Th were determined and compared with quasiparticle random-phase-approximation calculations. A large number of E1 transitions were observed for the first time in actinide nuclei with summed strength of 3.28(69)x10{sup -3} e{sup 2} fm{sup 2}. The observed summed M1 strength of 4.26(63){mu}{sub N}{sup 2} is in good agreement with the other actinides and with the systematics of the scissors mode in deformed rare-earth nuclei.},
doi = {10.1103/PHYSREVC.83.034615},
url = {https://www.osti.gov/biblio/21499509}, journal = {Physical Review. C, Nuclear Physics},
issn = {0556-2813},
number = 3,
volume = 83,
place = {United States},
year = {Tue Mar 15 00:00:00 EDT 2011},
month = {Tue Mar 15 00:00:00 EDT 2011}
}