In-Beam study of neutron deficient100Cd

Abstract

The very neutron deficient nucleus i~176 has been identified in the reaction 46Ti (58Ni, 2p2n) and its level scheme was studied up ~oEx = 4.3 MeV and I =12. A TI/2 = 40 10ns isomer was found at Ex=2.548 MeV with I~:(8+).Between the doubly magic shell closures at 4~ and 208pb the exotic "far-off-stability" nuclei close to lO~ are the only probes, accessible to in-beam spectroscopy, where a clear cut shell structure is expected and, hence, the residual nucleon-nucleon interaction can be studied. Shell model studies of less neutron deficient nuclei with N = 49 and N = 50 [I-3] have established a set of effective two-body matrix elements that account well for the proton structure of the N = 50 isotones in the upper g9/2 shell [4][5][6]. The strong proton-neutron interaction, which is responsible for the rapid evolution of deformation towards the Z-40, N = 40 and N = 60 regions, needs further investigation, since it fails to reproduce the spin gap isomerism in 95pd [7] and in the core excited 96 I00

In-beam spectroscopy of104Sn

“…[12] for j = g7/2, Sl/2, d3/2 and from experiment (92Nb) forj = d5/2. The present choice of TBME for the nn, nv and vv interaction gives a satisfactory description of the N=51 isotones, the N=52 nucleus 100Cd [2] and 104,1068n including the ground state binding energies. Nevertheless it should be regarded only as a starting point for a comprehensive shell model study of nuclei close to 100Sn between the N=50 isotone and Z=50 isotope series.…”

“…The observed Doppler shifts exclude an assignment of the respective y-rays to the light contaminants, as the corresponding shifts should be 50% larger. The population cross section was determined from the coincidence intensities relative to strongly populated prompt exit channels for which the cross section was determined from B+/EC decay intensities [2]. The experimental value o= 5(3) mb compares well with the CASCADE [9] prediction, o = 5 mb, when averaged over the 40 MeV energy loss of the 245 MeV 58Ni ions in the target.…”

“…The spectroscopic approach to the extremely neutron deficient doubly magic 94 has made substantial progress recently. 97Ag [1] and lo0Cd [2] have been studied in-beam and 98Ag in the 13+/EC decay of 98Cd [3] . From these studies fairly good knowledge of the proton-proton.…”

The decay of theI ?=8+ isomer in100Cd-neutron particle and proton hole states

“…Excited states of l~176 were first identified in-beam by Alber et al [1], and the 7-decay, half life and g-factor of the I~=(8 +) isomer were determined in two successive publications [2,3]. A shell model analysis of the existing data [3] revealed a predominant proton rgg/2 -2 configuration for the isomer and neutron nature for the lower spin states connected by the (8+)~(6 +) 4(4+)4(2+)--*0 + E2 cascade.…”

“…The detectors were positioned in two rings at 90+250 relative to the beam, and, in view of the low multiplicity of delayed 'y-rays, were used without collimators to suit the large source diameter of 8 cm. Filter detectors for neutrons (6 segments) [5] and charged particles (4 segments) [6] surrounded the target, as de-* Senior U.S. Scientist Humboldt Fellow on leave from SUNY, Stony Brook, N.Y., USA scribed elsewhere [7].…”