Constant-temperature level densities in the quasi-continuum of Th and U isotopes - Archive ouverte HAL Access content directly
Journal Articles Physical Review C Year : 2013

Constant-temperature level densities in the quasi-continuum of Th and U isotopes

, (1) , , (1) , , , , , (2) , , , (3) , , , , , , ,
1
2
3
M. Guttormsen
  • Function : Author
J. N. Wilson
L. A. Bernstein
  • Function : Author
Q. Ducasse
  • Function : Author
F. Giacoppo
  • Function : Author
A. Goergen
  • Function : Author
T. W. Hagen
  • Function : Author
A. C. Larsen
  • Function : Author
B. Leniau
  • Function : Author
T. Renstroem
  • Function : Author
S. J. Rose
  • Function : Author
S. Siem
  • Function : Author
T. Tornyi
  • Function : Author
G. M. Tveten
  • Function : Author
M. Wiedeking
  • Function : Author

Abstract

Particle-gamma coincidences have been measured to obtain gamma-ray spectra as a function of excitation energy for 231-233Th and 237-239U. The level densities, which were extracted using the Oslo method, show a constant temperature behavior. The isotopes display very similar temperatures in the quasi-continuum, however, the even-odd isotopes reveal a constant entropy increase Delta S compared to their even-even neighbors. The entropy excess depends on available orbitals for the last unpaired valence neutron of the heated nuclear system. Also, experimental microcanonical temperature and heat capacity have been extracted. Several poles in the heat capacity curve support the idea that an almost continuous melting of Cooper pairs is responsible for the constant-temperature behavior.

Dates and versions

in2p3-00854657 , version 1 (27-08-2013)

Identifiers

Cite

M. Guttormsen, B. Jurado, J. N. Wilson, M. Aiche, L. A. Bernstein, et al.. Constant-temperature level densities in the quasi-continuum of Th and U isotopes. Physical Review C, 2013, 88, pp.024307. ⟨10.1103/PhysRevC.88.024307⟩. ⟨in2p3-00854657⟩
29 View
0 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More