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Search and analysis of superdeformed and oblate states in {sup 193}Pb nucleus with the EUROGAM II multidetector array; Recherche et analyse des etats superdeformes et aplatis dans le noyau {sup 193}Pb a l'aide du multidetecteur EUROGAM II

Abstract

This work is devoted to the search and analysis of superdeformed and oblate states in {sup 193}Pb nucleus. High spin states of this isotope, populated via fusion-evaporation reaction {sup 168}Er ({sup 30}Si, 5n) {sup 193}Pb, have been studied with the EUROGAM II {gamma} multidetector array located near the VIVITRON accelerator in Strasbourg. New sorting and analysis programs have been developed in particular related to the background treatment. Angular distribution and linear polarisation analysis allowed us to assign the {gamma} transition multipolarities. Five dipole bands, corresponding to a weakly oblate-deformed shape of the nucleus, have been observed and connected to the low-lying states. The level scheme has been considerably extended up to a spin of 61/2 {Dirac_h} and an excitation energy of about 8 MeV. These structures have been interpreted as based on a high-K two-quasi-proton excitation coupled to rotation aligned quasi-neutrons. Six superdeformed bands, corresponding to a high prolate-deformed shape of the nucleus, have been observed. These six bands have been interpreted as three pairs of signature partners based on quasineutron excitations. The extraction of the g-factor of a K=9/2 neutron superdeformed orbital has been done for the first time in lead isotopes, giving access to the magnetic properties of  More>>
Authors:
Ducroux, L [1] 
  1. Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire
Publication Date:
Jan 09, 1997
Product Type:
Thesis/Dissertation
Report Number:
LYCEN-T-97-08
Reference Number:
EDB-00:108728
Resource Relation:
Other Information: TH: These (D. es Sc.); 196 refs; PBD: 9 Jan 1997
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; BCS THEORY; BGO DETECTORS; COINCIDENCE SPECTROMETRY; CRANKING MODEL; DATA PROCESSING; E2-TRANSITIONS; ENERGY SPECTRA; ERBIUM 168 TARGET; FOUR-PI DETECTORS; GAMMA SPECTROSCOPY; GE SEMICONDUCTOR DETECTORS; HARTREE-FOCK METHOD; LEAD 193; M1-TRANSITIONS; MAGNETIC PROPERTIES; NILSSON-MOTTELSON MODEL; NUCLEAR MATTER; OCTUPOLAR CONFIGURATIONS; POLARIZATION; ROTATIONAL STATES; SILICON 30 REACTIONS; SUPERDEFORMED NUCLEI; VIVITRON TANDEM ACCELERATOR; WOODS-SAXON POTENTIAL
OSTI ID:
20056799
Research Organizations:
Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire
Country of Origin:
France
Language:
French; English
Other Identifying Numbers:
TRN: FR9704882017851
Availability:
Available from INIS in electronic form
Submitting Site:
FRN
Size:
166 pages
Announcement Date:

Citation Formats

Ducroux, L. Search and analysis of superdeformed and oblate states in {sup 193}Pb nucleus with the EUROGAM II multidetector array; Recherche et analyse des etats superdeformes et aplatis dans le noyau {sup 193}Pb a l'aide du multidetecteur EUROGAM II. France: N. p., 1997. Web.
Ducroux, L. Search and analysis of superdeformed and oblate states in {sup 193}Pb nucleus with the EUROGAM II multidetector array; Recherche et analyse des etats superdeformes et aplatis dans le noyau {sup 193}Pb a l'aide du multidetecteur EUROGAM II. France.
Ducroux, L. 1997. "Search and analysis of superdeformed and oblate states in {sup 193}Pb nucleus with the EUROGAM II multidetector array; Recherche et analyse des etats superdeformes et aplatis dans le noyau {sup 193}Pb a l'aide du multidetecteur EUROGAM II." France.
@misc{etde_20056799,
title = {Search and analysis of superdeformed and oblate states in {sup 193}Pb nucleus with the EUROGAM II multidetector array; Recherche et analyse des etats superdeformes et aplatis dans le noyau {sup 193}Pb a l'aide du multidetecteur EUROGAM II}
author = {Ducroux, L}
abstractNote = {This work is devoted to the search and analysis of superdeformed and oblate states in {sup 193}Pb nucleus. High spin states of this isotope, populated via fusion-evaporation reaction {sup 168}Er ({sup 30}Si, 5n) {sup 193}Pb, have been studied with the EUROGAM II {gamma} multidetector array located near the VIVITRON accelerator in Strasbourg. New sorting and analysis programs have been developed in particular related to the background treatment. Angular distribution and linear polarisation analysis allowed us to assign the {gamma} transition multipolarities. Five dipole bands, corresponding to a weakly oblate-deformed shape of the nucleus, have been observed and connected to the low-lying states. The level scheme has been considerably extended up to a spin of 61/2 {Dirac_h} and an excitation energy of about 8 MeV. These structures have been interpreted as based on a high-K two-quasi-proton excitation coupled to rotation aligned quasi-neutrons. Six superdeformed bands, corresponding to a high prolate-deformed shape of the nucleus, have been observed. These six bands have been interpreted as three pairs of signature partners based on quasineutron excitations. The extraction of the g-factor of a K=9/2 neutron superdeformed orbital has been done for the first time in lead isotopes, giving access to the magnetic properties of the extreme nuclear matter. All these results have been discussed in terms of microscopic mean field self-consistent Hartree-Fock calculations using the microscopic 'rotor + particle(s)' model. (author)}
place = {France}
year = {1997}
month = {Jan}
}