The use of an array of six Euroball Cluster detectors, i.e. 42 large-volume germanium detectors, for beta-decay studies is described. The solid angle with respect to a source placed in the center of ...the array amounts to 65% of 4π sr. The total photo-peak efficiency for 1.33
MeV γ-rays is 10.2(5)%, without “adding back” the Compton-scattered events. For this γ-ray energy, the energy resolution of the entire setup is 2.8
keV. The performance of the array up to γ-ray energies of 8
MeV is discussed, and alternative ways of determining the photo-peak efficiency are presented.
Peripheral fragmentation of a 240 MeV/nucleon beam of the halo nucleus He-6 incident on carbon target has been studied in a kinematically complete experiment. It is found that one-neutron stripping ...to the unbound nucleus He-5 is the dominant fragmentation mechanism and that it leads to a spin alignment of He-5 in a plane perpendicular to the He-5 momentum vector. This is expected to be a common feature for all neutron halo nuclei.
In the rare-earth region of the nuclear table around the quasi-doubly magic nucleus Gd-146 is one of the very few places in which the Gamow-Teller (GT) resonance can be populated in beta decay. The ...appropriate technique to study such a phenomenon is the total absorption spectroscopy, thanks to which one can measure the B(GT) distribution in beta-decay experiments even when it is very fragmented and lies at high excitation energy in the daughter nucleus. These results on the GT resonance measured in the beta decay of the odd-Z, N = 83 nuclei Tb-148, Ho-150, and Tm-152 are presented in this work and compared with shell-model calculations. The tail of the resonance is clearly observed up to the limit imposed by the Q value. Our observation is important in the context of the understanding of the "quenching" of the GT strength.
In two complementary measurements, an array of high-resolution germanium detectors and a total-absorption
γ-spectrometer were used to investigate the
β decay of
102In, a one proton–hole, ...three-neutron particle nucleus with respect to the
100Sn core. A total of 509
β-delayed
γ rays (494 new) were observed for
102In, and a scheme comprising 234 levels (223 new) was constructed for the decay daughter
102Cd. The
Q
EC value of the decay and the half-life were determined, the latter one being 23.3(1) s. The summed Gamow–Teller strength deduced from the high-resolution experiment is as low as 0.60±0.07±0.11 compared to a value of 4.70±0.05±0.20±1.0 obtained from the total absorption measurement, and to a shell-model prediction of 13.3.
The decay-out spectrum of the superdeformed yrast band in {sup 192}Hg comprises a quasicontinuum, from which about 50 weak discrete transitions of energy between 1 and 3.2 MeV are resolved. The ...fluctuations of the one-dimensional quasicontinuum spectrum are studied with the fluctuation analysis method, which shows that of the order of a few thousand different transitions are available in the first step of the decay-out cascades. The experimental effective number of transitions is compared to schematic theoretical calculations.
Total absorption spectroscopy of 58Cu decay Janas, Z.; Karny, M.; Fujita, Y. ...
The European physical journal. A, Hadrons and nuclei,
10/2001, Letnik:
12, Številka:
2
Journal Article
Recent developments at the GSI on-line mass separator Burkard, K.; Collatz, R.; Hellström, M. ...
Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms,
04/1997, Letnik:
126, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The experimental techniques used at the GSI on-line mass separator for decay studies of nuclei far from stability are described. Particular emphasis is put on recent developments made for ...investigating nuclei near
100Sn. The methods applied for identifying and studying the new isotopes
94Ag,
100In,
101Sn and
114Ba are used as examples.
Nuclear targets, recoil ion catchers and reaction chambers Dionisio, J.S.; Vieu, Ch; Schück, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/1998, Letnik:
414, Številka:
2
Journal Article
Recenzirano
The main features of nuclear targets, recoil ion catchers and reaction chambers used in nuclear spectroscopic investigations involving in-beam multi-e-
γ spectrometers are discussed. The relative ...importance of the δ-ray background due to the accelerated ion–target and the recoil-ion–target interaction is estimated. Its impact on the prompt low-energy electron measurements is stressed. Finally a few general features of the interplay between accelerated ion beams, targets and recoil ion catchers particularly relevant for these measurements are broadly discussed and illustrated with typical examples of in-beam e-
γ studies.
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