Search

The very proton-rich 71Kr isotope was produced through the in-flight fragmentation of 78Kr on a beryllium target at RIKEN – Nishina Center in order to study its β-decay properties. A stack of double-sided silicon strip detectors, called WAS3ABi, was used as the decay station, where the detection of ion implants, β-decays and β-delayed protons took place. Beta-delayed γ-rays were measured using a system of 84 HPGe detectors, called EURICA, surrounding the decay station. The main goal of the present study was the precise measurement of the half-life of 71Kr, as in the literature there is an almost 10 σ difference between the most precise independent results. Implant–β time correlations, implant–proton time correlations and implant–β–γ time correlations were all used to derive the half-life value, followed by a thorough investigation of systematic uncertainties for each method. As these values were found to be consistent, the weighted average t1/2 = 94.40+19ms is reported as a new half-life value in this work. Furthermore a total of 26 previously unreported γ following the β-decay of 71Kr were also identified in the analysis.

The isotopic production cross sections for the reactions of 136Xe induced by proton, deuteron and carbon at 168 MeV/u were obtained by using the inverse kinematics technique at RIKEN Radioactive Isotope Beam Factory. The target dependence of the cross sections was investigated systematically. It was found that for the light-mass products, the cross sections on carbon are larger than those on deuteron and proton. The measured cross sections on proton were compared with the previous data at higher reaction energies to study the energy dependence. The experimental results were compared with the theoretical calculations including both the intranuclear cascade and evaporation processes using PHITS and with the EPAX and SPACS empirical parameterizations.

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.