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Abstract:: A nuclear resonance fluorescence experiment on 88Sr has been performed with bremsstrahlung of 6.7 MeV endpoint energy. The γ-ray linear polarisation has been measured with a EUROBALL CLUSTER detector used as a Compton polarimeter. The results indicate positive parity for the J= 1 state at 4.742 MeV in 88Sr, in contrast to the previous interpretation as a 1− two-phonon (2+1⊗ 3−1) state and in conflict with the predictions of the quasiparticle-phonon model. On the basis of such calculations the 1+ state at 3.486 MeV may be considered as the 1+1 one-phonon state and the very strong 1+1→ 0+1 deexcitation as proton spin-flip 2p1/2→ 2p3/2 transition.

Abstract.: The neutron g 9/2 single-particle state in 57Ni has been unambiguously identified in a combined measurement of the linear polarization, angular distribution, and angular correlation of γ rays following the fusion-evaporation reaction 28Si(32S,2pn)57Ni at a beam energy of 90 MeV. The linear polarization was measured with a Euroball cluster detector and a prototype of an encapsulated six-fold segmented hexaconical Ge-detector. The spin of the 3701 keV level in 57Ni was confirmed to be I= 9/2 and its parity determined to be positive.

Abstract:: An in-beam experiment with the subcoulomb reaction 209Bi(3He, d*γγ)210Po at 20.5 MeV was performed with two Euroball Cluster detectors in Cologne. It closed the gap between the low energy levels of the level-scheme and the high energy levels found in 209Bi(3He, d)210Po and 208Pb(4He, t)210Po particle experiments. New branchings have been found and the (3He, d*γγ) reaction below the coulomb-barrier has been used successfully.

Excited states of the nucleus ¹²³Xe have been investigated with the fusion-evaporation-reaction ¹¹⁰Pd(¹⁸O,5n)¹²³Xe at 86 MeV beam energy, using the compton-suppressed Nordball-multidetector-system at the Niels-Bohr-Institute in Risø, Denmark. The level scheme of ¹²³Xe was extended up to a level of tentative 53/2⁺. Four excited bands of 3-quasiparticle-character were observed. Analyzing the directional correlation information, we could assign spin- and parity-values to all observed bands in ¹²³Xe. The observed band structures fit well into systematics of the neighboring nuclei ¹²⁵Xe and ¹²⁷Xe.

Abstract.: A new high-spin isomer in 145Sm was observed by in-beam γ-ray spectroscopy with the reaction 122Sn(27Al,3np) at 127 MeV performed at the Nordball multi-detector array in Roskilde. The excitation energy of the isomer was determined to be E x= 11147 keV, and using the generalized centroid-shift method its half-life was found to be T 1/2= (7.4 ± 1.0) ns.

Abstract:: An in-beam experiment with the reaction 122Sn(27Al,4np) at 127 MeV was performed at the Nordball multi-detector array in Roskilde. It provided evidence for a new high-spin isomer in 144Sm. This isomer with T 1/2= (2.6 ± 0.5) ns at an excitation energy E x= 9232 keV seems to belong to a family of isomers of similar configuration in neighbouring N= 82 nuclei.