G. Barreau

Improvements in the in-beam γ-ray spectroscopy provided by an ancillary detector coupled to a Ge γ-spectrometer: the DIAMANT-EUROGAM II example

For the first time the 4π γ-ray spectrometer EUROGAM II has been coupled to a 4π light charged particle detector array, DIAMANT, during a test experiment on the reaction 32S + 58Ni at 120 MeV beam energy. A very large improvement in the peak-to-background ratio of the γ-spectra has been found when EUROGAM II is triggered by DIAMANT to select an exit channel. A simple algebra has been developed which provides theoretical estimates in good agreement with these experimental results. It is demonstrated that, depending on both the γ-spectrometer and ancillary detector performances, much better peak-to-background can be obtained by such a coupling. For the same peak-to-background ratio, the use of an ancillary detector allows for a lower γ-ray coincidence level and therefore improves the statistics. Ways to select the most appropriate ancillary detector are given. The ability of the ancillary detector to provide a total Doppler shift correction is crucial for the improvement of the peak-to-background ratio.

High-spin structures of 124−131Te: Competition of proton- and neutron-pair breakings

The 124-131Te nuclei have been produced as fission fragments in two fusion reactions induced by heavy ions ( 12C + 238U at 90MeV bombarding energy and 18O + 208Pb at 85MeV) and studied with the Euroball array. Their high-spin level schemes have been extended up to 6MeV (even-A and 5MeV (odd-A excitation energies from the triple

High-spin states with seniorityv=4, 5, and 6 in119–126Sn

gamma

Measurements of (n,γ) neutron capture cross-sections with liquid scintillator detectors

-ray coincidence data. The

Lifetimes of yrast rotational states of the fission fragments 100Zr and 104Mo measured using a differential plunger

gamma

High-spin structures of five N = 82 isotopes: 54 136 Xe, 55 137 Cs, 56 138 Ba, 57 139 La, and 58 140 Ce

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Exploring the emission barriers in hot nuclei

gamma

The Neutrons for Science Facility at SPIRAL‐2

angular correlations have been analyzed in order to assign spin and parity values to most of the observed states. Moreover the half-lives of isomeric states have been measured from the delayed coincidences between the fission-fragment detector SAPhIR and Euroball, as well as from the timing information of the Ge detectors. The behaviors of the yrast structures identified in the present work are first discussed in comparison with the general features known in the mass region, particularly the breakings of neutron pairs occupying the

The DIAMANT electronics and data acquisition system

nu

Correction method for Doppler broadened γ-ray lines using the linear momentum of the evaporated charged particles in heavy-ion induced fusion–evaporation reactions

h11/2 orbit identified in the neighboring Sn nuclei. The experimental level schemes are then compared to shell-model calculations performed in this work. The analysis of the wave functions shows the effects of the proton-pair breaking along the yrast lines of the heavy Te isotopes.