V. Kunze

Spin alignment of43Sc produced in the fragmentation of 500 MeV/u46Ti

In the fragmentation of 500 MeV/u46Ti the spin alignment of43mSc (I=19/2−, T1/2=473 ns) fragments was observed by the Time Dependent Perturbed Angular Distribution (TDPAD) method. The measurement was performed for different cuts in the longitudinal momentum distribution. A positive spin alignment of about 35% was observed in the center and a negative alignment of about 15% in the wing of the distribution. For the different cuts the relative production of the 19/2− state was measured. In the wing of the distribution the isomeric ratio N(19/2−)/total43Sc is about 15 times larger than in the center. The results of this pilot experiment are discussed in the frame of a shell-model.

β-decay of37Ca

Abstract The β-decay of 37Ca has been studied. The half-life was remeasured with improved precision to be 181.1 ± 1.0 ms, and β-delayed γ-rays were observed for the first time. The surprisingly high Γ γ Γ p values for proton-unbound states in 37K drastically reduce former discrepancies between the Gamow-Teller strength values B(GT) measured in the 37Ca β-decay and those deduced from the 37Cl(p,n)37Ar mirror reaction.

Gamow-Teller strength in the β-decay of 36Ca

Abstract The β-decay of 36 Ca has been studied at the projectile fragment separator at GSI Darmstadt. The measured Gamow-Teller strength function B (GT), deduced from the observed β-delayed proton- and γ-emission and from the measured half-life of 102(2) ms, is compared to results obtained from large-scale sd -shell model calculations. A systematic underestimation of the measured strength by the theory is found.

Investigation of new neutron-rich gold isotopes203Au and205Au

Using a208Pb beam of the UNILAC accelerator at GSI we produced the new isotopes203Au and205Au and identified them by measuring theirβ-decay properties. Their half-lives were found to be 60(6)s and 31(2)s, respectively, and theQ-value of203Au was determined to beQβ=2040(60)keV. Nuclear structure information of203,205Hg was derived from this measurement. Furthermore, production cross-sections of203,205Au are given and compared to those obtained in other experiments.

Evidence for the Iπ=8−, K=8 isomeric state in184Hf

Using an 11.4MeV/u136Xe beam of the UNILAC accelerator of GSI and anatW target, A=184 isobars were produced and separated by using an on-line mass separator. A new isomeric state was found in184Hf. This state decays with a half-life of 48(10) s and emits three γ-rays of 73, 482, and 555 keV as well as lower-lying cascade transitions. The hindrance of the 73 keV-E1 transition with ΔK=8 is compared with those of other even-even hafnium isotopes. The half-life of184Lu was estimated to be between 15 and 25s.

Spectroscopic investigations of179Yb-decay including a Ms-isomer in Lu

The neutron-rich isotope179Yb was produced by using the multinucleon transfer reactions 11.6 MeV/u136Xe+Re and 11.4 MeV/u197Au+W. The isotope identification was achieved by combining mass-separation and decay spectroscopy. A decay scheme was constructed including a new isomeric state in179Lu with a half-life of 3.1(9) ms.

Remeasurement of capture to positron decay ratios in22Na and65Zn and comparison with theory

In the decay of22Na theEC/β+ ratio for theβ-transition to the 1275 keV-level was measured to beEC/β+=0.1050 (29). Single and coincidence counting was performed using a 16% Ge(Li) and an NaI well-type detector. For65Zn theK/β+ ratio for the ground state transitionK1/β+=30.3 (10) was obtained using the same apparatus and in addition a 10 mm diam. × 5.4 mm Si(Li) detector. The results are compared with earlier experiments and with theory.