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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 proved essential to resolve these two excited states. Strongly populated levels observed at 3.30 and 4.05 (±0.05) MeV are candidates for negative parity states. Further analysis of the differential cross sections is in progress, with the aim of improving the identification of the higher lying states and determining absolute spectroscopic factors. more...

Several nuclei in the A ∼ 190 region have been studied following deep-inelastic reactions using a 460 MeV 82 Se projectile impinging upon a thick 192 Os target. The GASP array (at the Legnaro National Laboratory in Italy) was used to measure the resulting γ-decays. The previously reported near-yrast structure of 191 Os is extended to a t 1 /2= 61 ns isomer, at an energy of 2640 keV. Branching ratios for ΔI = 1 and A/ = 2 transitions in the K π = 11/2 + band have been measured, giving |(g K - g R )/Q 0 | = 0.022(3) and 0.024(7) for transitions from the 17/2 + and (19/2 + ) states respectively. These are consistent with the theoretical calculation for the proposed v11/2 + [615] configuration of the band. Nilsson plus BCS calculations reveal that the isomer is likely to have a {v11/2 + [615] ⊗ π11/2-[505] ⊗ π9/2-[514]} configuration with J π = K π = 31/2 + . This yields an implied reduced hindrance of f v = 1.9, in accordance with empirical systematics of K isomers in the A ∼ 180-190 region. more...

The yrast states of the beta-stable nucleus have been studied using the reaction at a beam energy of 65 MeV. Transitions in this nucleus were identified unambiguously using high-efficiency recoil-gated gamma-ray spectra obtained from the AYEBALL gamma-ray array in conjunction with the Argonne fragment mass analyser coupled to a split anode ionization chamber. The decay scheme is presented and it is hoped that such a study will shed light on the competition between core breaking and population of the neutron intruder orbitals in the generation of high angular momentum states in this region. more...

The excited states of the self-conjugate, odd-odd system, Ga have been investigated following the fusion-evaporation reaction at a beam energy of 65 MeV. Identification of candidate transitions in this nucleus were made using the AYEBALL -ray array following the selection of the recoil products with the Argonne fragment mass analyser (FMA) and a split anode ionization chamber. Spin assignments have been made on the basis of measured directional correlations from oriented states (DCO ratios). The resulting level scheme is presented and candidates for T = 1 and T = 0 structures suggested. more...

The very neutron-deficient isotope was produced in the reaction at 195 MeV and was identified using the Daresbury recoil separator. A pure -ray spectrum belonging to the de-excitation of the excited states of was obtained in-beam. Twenty -ray lines were identified, ten of them for the first time. The intensity balance concerning some of these -rays together with the results obtained from the coincident measurements show the existence of a new set of levels which may be interpreted as being a side band confirming the coupling of and configurations. more...

The gamma-decay of excited states in the neutron deficient isotopes Tc-87 and Tc-88 has been observed for the first time. The fusion-evaporation reactions Ni-58(S-32, p2n)Tc-87 and Ni-58(S-32, pn)Tc-88 at 110 MeV, Ca-40(Cr-50, p2n)Tc-87 and Ca-40(Cr-50, pn)Tc-88 at 170 MeV and Ni-58(Ar-36, alpha-pn)Tc-88 at 145 MeV beam energy were used. Unambiguous identification of these nuclei which are populated with less than 1 mb cross section was achieved with coincidences between the gamma-radiation and the evaporation residues detected in a recoil mass separator. From gamma-gamma-coincidence data, a decay scheme of 11 transitions was constructed for Tc-88, the ground state of which is suggested to have I-pi = 7- or 8+. Two transitions identified in Tc-87 follow the pattern of a g9/2 one-quasiparticle band. (Less) more...

The study of high-spin states in 79Sr is reported. The 79Sr nucleus was populated in the 58Ni(24Mg, 2pn)79Sr reaction at 65-110 MeV and the inverse 24Mg(58Ni, 2pn)79Sr reaction at 190 MeV bombarding energy. Using gamma - gamma and recoil- gamma - gamma coincidence techniques, the authors were able to extend the level scheme up to spins (37/2+) and (33/2-) in the positive and negative parity bands respectively. These spins are high enough to study the alignment effects due to protons in this mass region. more...

The high spin states in the the A = 61 isobars, and have been investigated using the AYEBALL -ray array at the Argonne National Laboratory, Chicago. Channel selection following a fusion-evaporation reaction was made using the fragment mass analyser in conjunction with a split anode ionization chamber to obtain isotopically pure -ray identification spectra. The decay schemes, together with spins assigned from a directional correlation analysis are presented and compared with previous work on these nuclei. more...

Gamow–Teller (GT) transitions starting from unstable pf-shell nuclei are of interest not only in nuclear physics, but also in astrophysics, e.g. in violent neutrino induced reactions at the core-collapse stage of type II supernovae. In the β-decay study of these pf-shell nuclei, half-lives can be measured rather accurately. On the other hand, in high-resolution (3He, t) charge-exchange reactions at 0°, individual GT transitions up to high excitations can be studied. Assuming the isospin symmetry for the strengths of Tz = ±1 → 0 analogous GT transitions, we present a unique 'merged analysis' for the determination of absolute B(GT) values. more...