[en] A digital pulse-shape discrimination algorithm for the identification of multi-site γ-ray interactions in coplanar CdZnTe detectors has been developed. The algorithm is used to suppress the Compton continuum in γ-ray spectroscopy measurements by rejecting the single-site events. The results of our study with a 15×15×7.5 mm³ detector demonstrate the effectiveness of this approach for revealing low intensity γ-ray peaks in the examined energy range (511–1274 keV), which is of importance for environmental and security applications. The method is also very useful for background reduction in the neutrinoless double beta-decay experiments for which coplanar CdZnTe detectors are of interest

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[en] A series of experiments devoted to the study of the neutron-rich N∼126 region have been performed at GSI, Darmstadt, within the Rare Isotopes Investigations at GSI (RISING) project. Exotic nuclei were synthesised using relativistic projectile fragmentation of 208Pb provided by the SIS synchrotron. The fragments produced were separated and identified event-by-event using the GSI FRagment Separator (FRS). The final reaction products were stopped in layers of plastic, copper, or double-sided-silicon-strip detectors [1] at the final focal point of the FRS and viewed by the high-efficiency, high granularity Stopped RISING gamma-ray spectrometer [2], consisting of 15 Euroball cluster Ge-detectors. Time-correlated gamma decays from individually identified nuclear species have been measured, allowing the clean identification of isomeric decays (passive stopper), and beta and conversion electron decays (active Si stopper). The highlights of the experimental results from these highly successful experiments include the first observation of excited states in three neutron-rich N=126 closed shell nuclei: (i) In 205Au79 the conversion electron decay of the seconds lived isomeric state into the πd3/2-1 ground-state has been observed [3]. In addition the yrast structure has been established up to spin-parity (19/2+) via the observation of the decay of in isomeric state with configuration π(h11/2-1)10S1/2; (ii) In 204Pt78, the yrast sequence has been observed following the internal decay of Iπ=(5-), (7-) and (10+) isomeric states [4]; (iii) In 203Ir77 excited states have been observed following the decay of an isomeric state with structure similar to that in its 205Au isotone. Shell model calculations have been performed in order to get a deeper understanding of the structure of these N=126 nuclei. It was found that in order to get a good description for all available information on the N=126 isotones below lead, both on excitation energies and transition strengths, small modifications of the standard two-body matrix elements [5] were required. The possible consequences of these modifications on the structure of the more exotic N=126 nuclei as approaching the r-process waiting points is investigated. Experiments, results, comparison with theoretical calculations and future plans will be discussed.(author)

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[en] The ¹⁸⁰Re nucleus has been studied at high angular momentum using the ¹⁷⁴Yb(¹¹B, 5n) reaction at the Australian National University, with the CAESAR array for γ-ray detection and the Super-E solenoid for electron-conversion measurements. A τ = 13 ± 1 μs, 6-quasiparticle isomer and two intrinsic states and their associated bands have been established. The validity of the K quantum number is discussed. (author)

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