Study of two phonon octupole vibrations in 146Gd
| dc.contributor.advisor | Orce, J.N. | |
| dc.contributor.author | Khumalo, Nontobeko Angel | |
| dc.date.accessioned | 2014-07-23T13:00:52Z | |
| dc.date.available | 2014-07-23T13:00:52Z | |
| dc.date.issued | 2013 | |
| dc.description | Dissertation submitted in partial fulfillment of the requirements for the degree of Master of Science in the Department of Physics and Engineering at the University of Zululand, South Africa, 2013. | en_US |
| dc.description.abstract | Recent measurements of double octupole vibrational states in 146Gd have resulted in the need of deeper studies of such excitations. A state with J =6+ at 3485 keV has been suggested as the two-phonon octupole excitation in 146Gd. A 6+ ! 3 ! 0+ cascade of E3 -ray transitions from this state supports this interpretation This work aims at investigating this 6+ state and the other missing members of the octupole quartet are sought in order to accurately characterize the two-phonon octupole vibrations in nearly-spherical nuclei. The coincidence experiment, with the 144Sm( , 2n)146Gd fusion-evaporation reaction at a beam energy of 26.3 MeV, was performed to produce the 146Gd nucleus. The experiment was performed using the AFRODITE array at iThemba Laboratory for Acceletor-Based Sciences (LABS), South Africa. Eight clover detectors were used, with four at 90 and four at 135 , and they were surrounded by the BGO shields for compton suppression. With the highly e cient AFRODITE array, the experiment provided good quality data which was sorted into matrices. From these matrices, the total projection spectrum was obtained. A gate on a 382 keV -ray transition was made to see if the suggested 1905 keV -ray transition from the J = 6+ state to the J = 3 state will be observed. From the 382 keV gated spectrum, there was no evidence of the 1905 keV -ray transition. The branching ratios of the 826 and 502 keV transitions were measured and the limit to the intensity of the 1905 keV peak has been set. The limit was set to 6 intensity for the unobserved 1905 keV -ray transition . Our work show no evidence of the 1905 keV -ray transition and thus no octupole vibrations in 146Gd. However, limitations in the sensitivity of our experiment may leave an open door to further investigate the existence of the two-phonon octupole excitation in 146Gd nucleus. | en_US |
| dc.description.sponsorship | National Research Foundation and SANHARP | en_US |
| dc.identifier.uri | https://hdl.handle.net/10530/1348 | |
| dc.language.iso | en | en_US |
| dc.publisher | University of Zululand | en_US |
| dc.subject | Phonon octupole vibrations | en_US |
| dc.title | Study of two phonon octupole vibrations in 146Gd | en_US |
| dc.type | Thesis | en_US |