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The decay of the extremely neutron-deficient isotope 45Fe has been studied by using a new type of gaseous detector in which a technique of optical imaging is used to record tracks of charged particles. The two-proton radioactivity and the $ \beta$ -decay channels were clearly identified. For the first time, the angular and energy correlations between two protons emitted from the 45Fe ground state were measured. The obtained results were confronted with predictions of a three-body model. [ABSTRACT FROM AUTHOR]

The decay of extremely neutron-deficient isotope 45Fe has been studied using a new type of gaseous detector in which a technique of optical imaging is used to record tracks of charged particles. The two-proton radioactivity and the &decay;-decay channels accompanied by proton(s) emission were clearly identified. For the first time, the angular and energy correlations between two protons emitted from the 45Fe ground-state were measured. The obtained distributions were confronted with predictions of three-body model. Studies of β-decay channels of 45Fe provided first unambiguous evidence for the β-delayed three proton emission. [ABSTRACT FROM AUTHOR]

The evolution of the π h11/2ν h11/2 and π h11/2ν s1/2 isomeric configurations was studied for the N = 77 isotones near the proton drip line. The decays of metastable levels in 140Eu, 142Tb , and 144Ho were measured by means of X-, gamma- and conversion electron spectroscopy at the Recoil Mass Spectrometer at Oak Ridge. The sequence of isomeric levels in 140Eu was experimentally determined. The half-life of the π h11/2ν h11/2 state in 142Tb was remeasured to be 25(1) μs. The spins and parities of 5- and 8+ for the π h11/2ν s1/2 and π h11/2ν h11/2142Tb isomers, respectively, were established from measured multipolarities. No evidence for the expected 1+ ground state was found in the 144Ho decay data. [ABSTRACT FROM AUTHOR]

Measurement of fine structure in proton emission allows one to deduce the composition of the parent and daughter state’s wavefunction populated by proton emission. This paper presents new experimental data on the fine-structure decay of 146Tm, and a new interpretation of its decay properties. [ABSTRACT FROM AUTHOR]

We report the results from the first experiment to measure gyromagnetic factors of μs isomers in neutron-rich nuclei produced by intermediate-energy projectile-fragmentation reactions. The Time Dependent Perturbed Angular Distribution (TDPAD) method was applied in combination with the heavy-ion-gamma correlation technique. The nuclides in the vicinity of 68Ni were produced and spin-oriented following the fragmentation of a 76Ge, 61.4 MeV/u beam at GANIL. The results obtained, |g|(69mCu) = 0.225(25) and |g|(67mNi) = 0.125(6) provide another indication of the importance of proton excitation across the Z = 28 shell gap for the description of these states. [ABSTRACT FROM AUTHOR]

In the experiment performed at the LISE2000 spectrometer at GANIL neutron-rich nickel isotopes were studied by microsecond isomer spectroscopy. Evidence for an isomer in 76Ni is found, consistently with the shell model prediction of an 8+ state of v(g9/2)² structure. [ABSTRACT FROM AUTHOR]

γ-ray transitions in 134Te, 135Te, and 136Te were measured from 9Be-induced reactions with a radioactive 132Sn beam at a sub-Coulomb barrier energy of 3 MeV per nucleón using particle-y coincidence spectroscopy. The transitions were selected by gating on alpha-like particles in a Csl detector following a combination of (9Be,aln), (9Be,α2n), and (9Be,α3n) incomplete fusion-evaporation reactions. Distorted-wave Born approximation calculations suggest little to no contribution from the (9Be,7He), (9Be,6He), and (9Be,5He) direct reactions, γ-ray transitions from previously known 2+ ⊗ v2∫/7/2 and 4+ ⊗ v2∫/7/2 multiplet members in 135Te are observed. A new y ray is observed, assigned to the third-excited state in 135Te, and new 2+ ⊗ v2∫/7/2 multiplet members are suggested. In addition, spin assignments are made by using recent one-neutron transfer data. The updated experimental data for, 135Te are compared to shell-model calculations for a relatively complete set of states up to the yrast 15/2-,4+⊗ v2∫/7/2 multiplet member at 1505 keV. [ABSTRACT FROM AUTHOR]

Background: The nuclei in the region around 68Ni display an apparent rapid development of collectivity as protons are removed from the f1/2 single-particle state along the N = 40 isotonic chain. Proton and neutron excitations across the Z = 28 and N = 40 gaps are observed in odd-A 27Co and 26Fe isotopes. Little spectroscopic information beyond the excited 2+ and 4+ is available in the even-even ... Fe nuclei to compare with shell model calculations. Purpose: Our goal is to determine the low-energy level schemes of 66,68Fe and compare the observed excitations with shell model calculations to identify states wherein a contribution from excitations across Z = 28 and N = 40 are present. Method: The low-energy states of 66,68Fe were populated through the beta decay of 66,68Mn produced at the National Superconducting Cyclotron Laboratory. Beta-delayed gamma-ray transitions were detected and correlated to the respective parent isotope to construct a low-energy level scheme. Results: The low-energy level schemes of 66,68Fe were constructed from observed gamma-ray coincidences and absolute gamma-ray intensities. Tentative spin and parity assignments were assigned based on comparisons with shell model calculations and systematics. The two lowest 0+ and 2+ states were characterized in terms of the number of protons and neutrons excited across the respective shell gaps. Conclusion: The removal of two protons from 68Ni to 66Fe results in an inversion of the normal configuration and the one characterized by significant excitation across the Z = 28 and N = 40 gaps. Approximately, one proton and two neutrons are excited across their respective single-particle gaps in the ground state of 66Fe. [ABSTRACT FROM AUTHOR]

The low-energy level structures of 6425Mn39 and 6625Mn41 were investigated through both the decay of Mn metastable states and the population of levels following the &bgr; decay of MCr and 64Cr and 66 Cr. The deduced level schemes and tentatively assigned spins and parities suggest the coexistence of spherical and deformed configurations above and below N = 40 for the odd-odd Mn isotopes. The low-energy deformed configurations are attributed to the coupling between a proton in a K = 1/2- level with neutrons in either the K = 1/2- or the K = 3/2+ levels originating from the π3/2, νp1/2, and νg9/2 single-particle states, respectively. [ABSTRACT FROM AUTHOR]

The β+ decay of very neutron-deficient 43Cr was studied by means of an imaging time projection chamber that allowed recording tracks of charged particles. Events of β-delayed emission of one, two, and three protons were clearly identified. The absolute branching ratios for these channels were determined to be (81±4)%, (7.1±0.4)%, and (0.08±0.03)%, respectively. 43Cr is thus established as the second case in which the β-3p decay occurs. Although the feeding to the proton-bound states in 43V is expected to be negligible, the large branching ratio of (12±4)% for decays without proton emission is found. [ABSTRACT FROM AUTHOR]