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Beta decays of 94,96Ag and 103Sn nuclei into proton channels have been studied in the recent experiments at the GSI-ISOL facility. New efficient and chemically selective ion sources provided the highest yields of light silver and tin isotopes. Large arrays of germanium γ-ray and silicon charged-particle detectors, as well as a total absorption spectrometer (TAS) were used to measure β-proton, proton-γ, β-proton-γ and proton-γ-γ spectra. For the decay of 94Ag, we observed high-spin states in 93Rh populated by proton emission following β decay, whose largest spin value (≥39/2) yields an experimental proof for the existence of a second high-spin isomer in 94Ag with I≥17. Its β-decay energy is at least 16.8 MeV, corresponding to an excitation energy ≥5.5 MeV. For 103Sn, the γ rays measured in coincidence with β-delayed protons allowed us to establish the β-decay properties of this isotope. In particular, a QEC value of 7.5(6) MeV is derived from the intensity ratio of protons that are preceded either by EC or by β+ decays and populate the 2+ state in 102Cd.

In a series of experiments at the SISSI/LISE3 facility of GANIL conducted between 1999 and 2004, we have collected decay information for proton-rich nuclei between {sup 36}Ca and {sup 56}Zn. The data allowed us to study the decay properties of 26 nuclei. The main experimental information obtained for all nuclei is their {beta}-decay half-life and their total {beta}-delayed proton emission branching ratio. For many nuclei, individual proton groups and {gamma} rays were identified and allowed us to establish first partial decay schemes for some of the nuclei studied. In addition, mass-excess values have been determined for some of the nuclei by means of the isobaric multiplet mass equation. For {sup 50}Ni, the decay via {beta}-delayed two-proton emission could be tentatively identified. The decay of {sup 49}Ni allowed for the first time to identify the first 2{sup +} state in {sup 48}Fe. The experimental data are confronted to model predictions for the half-life and the mass-excess values.

The production cross-sections of proton-rich protactinium and thorium isotopes have been investigated for the fragmentation of 1 A GeV 238 U in a beryllium target at the SIS/FRS facility at GSI Darmstadt. The experimental results are compared with the predictions of an abrasion-ablation model of nuclear fragmentation yielding good overall agreement. Weak evidence for flrst observation of new isotopes 208 Th and 211 Pa is presented.

A new way of study the reaction of triple radiative capture αα(n,γ)9Be is demonstrated. At the GSI-ISOL facility, we have measured the γ decays of excited 1/2+, 5/2− and 1/2− states in 9Be, which are strongly populated in the β decay of 9Li. The respective partial γ-widths are of astrophysical interest in order to reliably estimate the αα(n,γ)9Be rates in SN type-II as a possible site of the synthesis of heavy elements in the Universe. The 9Li nuclei were implanted into a foil viewed by high-granularity arrays of β and γ detectors. The γ-ray spectra were measured in coincidence with the β-particles by selecting large β-γ angles in order to suppress the bremsstrahlung background. For the first time, the γ-rays from the 1/2+ and 5/2− states in 9Be were observed in 9Li decay, with the 1/2+-state energy and width measured to be 1689(10) and 224(7) keV, respectively, while the latter transition provided a reference point. The upper limit of the 1/2− partial γ-width is measured to be 7 ⋅ 10 6 MeV . An improved sensitivity experiment is feasible at facilities with the larger yield of 9Li.

The research programme at the GSI Online Mass Separator focuses on the study of exotic nuclei far from the valley of stability. Special emphasis is placed on the investigation of decay properties of isotopes along the N = Z line between the double shell closures at 56 Ni and 100 Sn. In this contribution, the major recent achievements along with the corresponding experimental methods are reviewed.