Multiple chiral bands in 193Tl

Ndayishimye, Joram (2016-03)

Thesis (PhD)--Stellenbosch University, 2016

Thesis

ENGLISH ABSTRACT : In order to extend knowledge about chirality in A ∼ 190 mass region, experiments were performed at iThemba LABS for γ−spectroscopy studies in 192,193Tl. Previous level scheme of 193Tl was considerably modified and extended. Level scheme of 192Tl was also significantly extended. Spins and parities were assigned to most of the levels. The yrast band in 192Tl is associated with πh9/2⊗νi13/2 configuration which is suitable for chiral symmetry. A side band with close excitation energies was observed, suggesting that the two bands in 192Tl might form a chiral pair. More interestingly three bands in 193Tl have similar properties and were associated with the same πh9/2 ⊗νi13/2 2. These bands might represent a multiplet of chiral bands in 193Tl. Theoretical calculations using the Cranked Nilsson-Strutinsky (CNS) model, the multi-particle rotor (MPR) model, and the two-quasiparticle-plus-triaxial rotor model (TQPRM) support the presence of chiral symmetry in 192,193Tl.

AFRIKAANSE OPSOMMING : Ten einde kennis oor chiraliteit in die ∼ 190 massa streek in te win, was eksperimente uitgevoer by iThemba LABS vir γ-spektroskopie studies in 192,193Tl. Die vorige vlak skema van 193Tl was aansienlik verander en uitgebrei. Die vlak skema van 192Tl was ook aansienlik uitgebrei. Spin en pariteite was toegeken aan die meeste van die vlakke. Die yrast band in 192Tl word geassosieer met die πh9/2 ⊗ νi13/2 konfigurasie wat geskik is vir chirale simmetrie. Sy band met noue opwekkings energie is waargeneem, wat aanduiding gee dat die twee bands in 192Tl dalk ’n chirale paar vorm. Meer interessant is dat die drie bande in 193Tl soortgelyke eienskappe het en was geassosier met die dieselfde πh9/2 ⊗ νi13/2 2 konfigurasie, wat geskik is vir chiraliteit. Hierdie bande mag dalk ’n multiplet van chirale bande in 193Tl verteenwoordig. Teoretiese berekeninge met behulp van die Cranked Nilsson-Strutinsky (CNS) model, die multi-deeltjie rotor (MPR) model en die twee-quasideeltjie-plus-triaksiaale rotor model (TQPRM) ondersteun die teenwoordigheid van chirale simmetrie in 192,193Tl.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/98454
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