0000000000548095
AUTHOR
C. N. Timis
Nucleon transfer via (d,p) using TIARA with a24Ne radioactive beam
NESTER; The first physics results measured using the TIARA array are reported. The reaction $^{24}$Ne(d,p)$^{25}$Ne has been studied in inverse kinematics with a radioactive beam of $^(24)$Ne provided by SPIRAL at GANIL. TIARA is very compact with a high geometrical coverage for charged particles, and is designed specifically for the study of transfer reactions in inverse kinematics, with radioactive beams. From the (d,p) differential cross sections, the ground state of $^{25}$Ne is assigned to have $J^\pi$ = $1/2^+$ and the lowest states with $J^\pi$ = $5/2^+$ and $3/2^+$ are tentatively identified at excitation energies of 1.70 and 2.05 (±0.05) MeV, respectively. Coincident gamma-ray data…
Beta-decay half-lives at the N = 28 shell closure
Abstract Measurements of the beta-decay half-lives of neutron-rich nuclei (MgAr) in the vicinity of the N =28 shell closure are reported. Some 22 half-lives have been determined, 12 of which for the first time. Particular emphasis is placed on the results for the Si isotopes, the half-lives of which have been extended from N =25 to 28. Comparison with QRPA calculations suggests that 42 Si is strongly deformed. This is discussed in the light of a possible weakening of the spin–orbit potential.
Migration of Nuclear Shell Gaps Studied in thed(Ne24,pγ)Ne25Reaction
The transfer of neutrons onto 24Ne has been measured using a reaccelerated radioactive beam of 24Ne to study the (d,p) reaction in inverse kinematics. The unusual raising of the first 3/2+ level in 25Ne and its significance in terms of the migration of the neutron magic number from N=20 to N=16 is put on a firm footing by confirmation of this state's identity. The raised 3/2+ level is observed simultaneously with the intruder negative parity 7/2- and 3/2- levels, providing evidence for the reduction in the N=20 gap. The coincident gamma-ray decays allowed the assignment of spins as well as the transferred orbital angular momentum. The excitation energy of the 3/2+ state shows that the estab…