Nuclear spectroscopy above isomers in 67148Ho81 and 67149Ho82 nuclei: Search for core-excited states in Ho149
Abstract
The excited states of Ho148 and Ho149 isotopes are studied using γ-ray and electron spectroscopy in off-beam and in-beam modes following Sn112,114(Ar40,xnyp) reactions. Experiments include measurements of single γ-rays and conversion electron spectra as well as γ-γ, electron-γ, γ-t, and γ-γ-t coincidences with the use of the OSIRIS-II 12-HPGe array and conversion electron spectrometer. Based on the present results, the level schemes of Ho148 and Ho149 are revised and significantly extended, up to about 4 and 5 MeV of excitation energy, respectively. Spin and parity of 5- are assigned to the 9.59-s isomer in Ho148 based on conversion electron results. Previously unobserved γ rays feeding the 10+ isomer in Ho148 and the 27/2- isomer in Ho149 nuclei are proposed. Shell-model calculations are performed. Possible core-excited states in Ho149 are discussed.
- Publication:
-
Physical Review C
- Pub Date:
- April 2010
- DOI:
- 10.1103/PhysRevC.81.044305
- Bibcode:
- 2010PhRvC..81d4305K
- Keywords:
-
- 27.60.+j;
- 23.20.-g;
- 21.60.Cs;
- 90<
- =A<
- =149;
- Electromagnetic transitions;
- Shell model