Experimental and shell-model study of excited states in and related notes on

The fusion-evaporation reaction at 125-MeV beam energy was used to populate excited states in . Combining the Gammasphere spectrometer with ancillary devices including the Microball CsI(Tl) array and a shell of neutron detectors, a comprehensive level scheme could be derived. The experimental results are compared with theoretical results from shell-model calculations. Taking into account isospin-symmetry breaking terms is found to considerably improve the shell-model description for . This motivated a predictive case study of near-yrast states in the mirror nucleus

Low-, medium-, and high-spin states in the N=Z+1 nucleus Ga 63

The fusion-evaporation reaction Si28+Ca40 at 122 MeV beam energy was used to populate excited states in the N=Z+1 nucleus Ga63. With the combination of the Gammasphere spectrometer and the Microball CsI(Tl) charged-particle detector array, the level scheme of Ga63 was extended by more than a factor of two in terms of number of γ-ray transitions and excited states, excitation energy (Ex>30MeV), and angular momentum (I>30ℏ). Nine regular sequences of states were newly established in the high-spin part of the level scheme. The majority of these rotational band structures could be connected to the previously known part of the level scheme by high-energy γ-ray transitions in the energy range Eγ=4-6MeV. Low-spin states were assessed by shell-model calculations. The high-spin rotational bands were interpreted and classified by means of cranked Nilsson-Strutinsky calculations

Single-particle and collective excitations in the N=28 isotones Fe 54 and Mn 53

The fusion-evaporation reaction S32+Si28 at 125 MeV beam energy was used to populate high-spin states in the semimagic N=28 nuclei Mn53 and Fe54. With a combination of the Gammasphere spectrometer and ancillary devices including the Microball CsI(Tl) array, extensive high-spin level schemes are derived. They exhibit rotational-like collective structures and competing single-particle excitations. The experimental results are compared with predictions from shell-model calculations, for which the inclusion of isopin-symmetry-breaking terms is found to improve the description. An interpretation of the high-spin states is put forward using cranked Nilsson-Strutinsky calculations, indicative of contributions from collective excitations beyond some 8-MeV excitation energy and highlighting the importance of the g9/2 intruder orbital in this energy range

Prompt Proton Decay Scheme of 59Cu

Five prompt proton decay lines have been identified between deformed states in Cu-59 and three spherical states in Ni-58 by means of high-resolution in-beam particle-gammagamma coincidence spectroscopy. The GAMMASPHERE array coupled to dedicated ancillary detectors including four DeltaE-E silicon strip detectors was used to study high-spin states in Cu-59. The multiple discrete proton lines are found to probe the wave functions of states in the decay-out regime of well- and superdeformed states

High-resolution In-beam Particle Spectroscopy - New Results on Prompt Proton Emission from 58Cu

Prompt proton decay lines in Cu-58 have been studied by means of high-resolution in-beam particle-gamma coincidence spectroscopy using the GAMMASPHERE Ge-detector array in conjunction with a dedicated set of ancillary detectors including four DeltaE-E silicon-strip telescopes. High-spin states in Cu-58 have been populated via the heavy-ion fusion-evaporation reaction Si-28(Ar-36, 1alpha1p1n) at 148 MeV beam energy. The full-width at half maximum for the proton peak could be reduced significantly compared to earlier experiments. The results indicate that only one prompt proton decay branch exists in the decay-out of the well-deformed band of Cu-58

Terminating states in the positive-parity structures of As 67

The energy levels and γ-ray decay scheme of the positive-parity states in the Tz=12 nucleus As67 have been studied by using the Ca40(Ar36,2αp)As67 reaction at a beam energy of 145 MeV. Two new band structures have been identified which can be connected to the previously known levels. The results for these bands are compared with configuration-dependent cranked Nilsson-Strutinsky calculations. The good level of agreement between theory and experiment suggests that these structures can be interpreted in terms of configurations that involve three g92 particles and that both possess noncollective terminating states

Onset of high-spin rotational bands in the N=Z nucleus Ga 62

The fusion-evaporation reaction Si28+Ca40 at 122 MeV beam energy was used to populate high-spin states in the odd-odd N=Z nucleus Ga62. With the combination of the Gammasphere spectrometer and the Microball CsI(Tl) charged-particle detector array the decay scheme of Ga62 was extended beyond 10 MeV excitation energy. The onset of band structures was observed. These high-spin rotational states are interpreted and classified by means of cranked Nilsson-Strutinsky calculations