# Spectroscopie gamma en ligne de noyaux légers riches en neutrons produits par fragmentation de faisceau radioactif et mesures de temps de vie des niveaux excités dans les noyaux proches de $^{68}$Ni

Abstract : This thesis deals with studies of nuclei far from the valley of stability produced at GANIL by projectile fragmentation at intermediate energies. It consists of two parts. The first one is dedicated to the study of very light exotic nuclei around N=14. This is the first time that online gamma-ray spectroscopy combined with the projectile fragmentation was used with radioactive incident beams at GANIL. The advantages and the limitations of this method were established. 40 different nuclei have been produced and studied at the same time. A strong dependence of the population of excited states on the type of projectile was observed. New information was obtained on the structure of the isotopes 14,15B, 17,18,19,20C, 18,19,20,21,22N, 22,23,24O, 24,25,26F and 29Ne. The level schemes obtained from this study have been compared with shell-model predictions. In particular, the energy of 1588(20) keV found for the first 2+ excited state in 20C, as well as the non-existence of a bound state in 24O, show that the protonneutron interaction plays an important role in the structure of these nuclei. In the second part, an experiment is presented concerning the neutron-rich isomer nuclei around 68Ni produced by the LISE spectrometer. The fast-timing method was applied for the first time for the study of nuclei produced by projectile fragmentation. Subnanosecond half-lives of several levels in 67,69,90Ni and 71,72Cu were measured simultaneously and with high precision. These results have allowed us to test the shell model predictions for several E2 transitions and their associated B(E2) transition probabilities.
Keywords :
Document type :
Theses

https://tel.archives-ouvertes.fr/tel-00002775
Contributor : Admin Base Des Publications de l'In2p3 <>
Submitted on : Tuesday, April 29, 2003 - 1:34:29 PM
Last modification on : Thursday, February 1, 2018 - 1:34:46 AM
Long-term archiving on: : Tuesday, September 11, 2012 - 8:20:28 PM

### Identifiers

• HAL Id : tel-00002775, version 1

### Citation

Mihai-Alexandru Stanoiu. Spectroscopie gamma en ligne de noyaux légers riches en neutrons produits par fragmentation de faisceau radioactif et mesures de temps de vie des niveaux excités dans les noyaux proches de $^{68}$Ni. Physique Nucléaire Théorique [nucl-th]. Université de Caen, 2003. Français. ⟨tel-00002775⟩

Record views