Population of high spin states by quasi-elastic and deep inelastic collisions

First in-beamγ-ray study of the level structure of neutron-richS39

“…Binary grazing reactions have been used to populate the nuclei of interest. The previous published works from the experiment have involved studies of the neutron-rich isotopes 33 Si 38 Cl [7]. These studies are mainly concerned with the role of negative-parity intruder orbitals in the structure of neutron-rich nuclei on the periphery of the island of inversion, which is centered on 32 Mg, and on the description of such nuclei using state-of-the-art shell-model calculations [8].…”

“…As a by-product of an investigation of the level structure of 45,46 Ar through in-beam γ -ray spectroscopy using the fragmentation of a 60 AMeV 48 Ca beam, Dombrádi et al [31] identified a γ -ray transition of energy 904(7) keV, which was attributed to 39 S. Thus, although the 339.9-, 398.6-, 465.5-, 904-, 1126.2-, and 1524.6-keV γ rays have been assigned to the decay of excited states of 39 S, to date none have been placed within a level scheme. Binary grazing reactions with stable neutron-rich beams and heavy targets can be used to populate yrast and nearyrast states of moderately neutron-rich projectilelike species [5,13,[32][33][34] and, in general, experiments using such reactions, although unable to reach the most neutron-rich nuclear species currently accessible to experiment, provide more detailed spectroscopy than is currently possible using intermediate-energy Coulomb excitation, where the states that are populated are, in general, those that are connected directly to the ground state by E2 transitions [35]. Fusion-evaporation reactions with stable beams are unable to populate neutron-rich nuclei such as 39 S. Here, the yrast decay sequence of 39 S, populated in binary grazing reactions, has been studied.…”

Intruder negative-parity states of neutron-richSi33

“…34 14 Si 20 lies outside the island of inversion and, although only two protons removed from the highly deformed 32 12 Mg 20 nucleus, is a spherical N = 20 closed-shell nucleus in its ground state. Further, although there is some uncertainty in the energy gap between the proton 1d 5/2 orbital (fully occupied in a simple shell-model picture of the 34 Si ground state) and the 2s 1/2 orbital (empty in the 34 Si ground state) as a consequence of an incomplete knowledge of the fragmentation of the proton 1d 5/2 single-particle strength, the separation is known to be large, giving the nucleus the characteristics of a doubly magic nucleus. In the work of Cottle [6], the splitting is given as about 7 MeV for 34 Si.…”

“…Further, although there is some uncertainty in the energy gap between the proton 1d 5/2 orbital (fully occupied in a simple shell-model picture of the 34 Si ground state) and the 2s 1/2 orbital (empty in the 34 Si ground state) as a consequence of an incomplete knowledge of the fragmentation of the proton 1d 5/2 single-particle strength, the separation is known to be large, giving the nucleus the characteristics of a doubly magic nucleus. In the work of Cottle [6], the splitting is given as about 7 MeV for 34 Si. In its ground state, 33 Si has a neutron hole in the 1d 3/2 orbit; neutron one particle-two hole configurations * zhimin.wang@uws.ac.uk will therefore play a dominant role in the structure of negativeparity states.…”

Particle-core coupling inS37

“…Binary grazing reactions with stable neutron-rich beams and heavy targets can be used to populate yrast and near yrast states of moderately neutron-rich projectile-like species [6][7][8][9][10]. In general, experiments using such reactions, although unable to reach the most neutron-rich nuclear species currently accessible to experiment, provide more detailed spectroscopy than is possible at the present time using fragmentation reactions [11] or intermediate-energy Coulomb excitation; in the latter case, the states that are populated are, in general, those that are connected directly to the ground state by E2 transitions [12].…”