Doppler shift as a tool for studies of isobaric analog states of neutron-rich nuclei: application to 7He.

We have developed a new technique to study exotic neutron-rich nuclei via their isobaric analog states (IAS). We populate high-isospin states in resonant reactions of radioactive ion beams with protons. Characteristic gamma rays emitted from excited decay products were used to identify the population of the IAS. We show that information on the differential and total cross section for formation of the IAS can be extracted from the energy spectrum of the Doppler-shifted gamma rays. This technique was applied to the study of T=3/2 states in 7Li, which are analogs of states in 7He. The analog of the 7He ground state was clearly observed, whereas the presence of the analog of a narrow 1/2(-) state at 0.6 MeV excitation in 7He reported by M. Meister et al. [Phys. Rev. Lett. 88, 102501 (2002)] was excluded at the 90% confidence level. Evidence is presented for a broad 1/2(-) state at a higher excitation energy in 7He.

Half-life of the doubly magic r-process nucleus 78Ni.

Nuclei with magic numbers serve as important benchmarks in nuclear theory. In addition, neutron-rich nuclei play an important role in the astrophysical rapid neutron-capture process (r process). 78Ni is the only doubly magic nucleus that is also an important waiting point in the r process, and serves as a major bottleneck in the synthesis of heavier elements. The half-life of 78Ni has been experimentally deduced for the first time at the Coupled Cyclotron Facility of the National Superconducting Cyclotron Laboratory at Michigan State University, and was found to be 110(+100)(-60) ms. In the same experiment, a first half-life was deduced for 77Ni of 128(+27)(-33) ms, and more precise half-lives were deduced for 75Ni and 76Ni of 344(+20)(-24) ms and 238(+15)(-18) ms, respectively.

[Animal welfare aspects regarding the raising of breeding ostriches in Germany]. / Tierschutzaspekte bei der Haltung von Zuchtstraussen in Deutschland.

The commercial housing of African Ostriches in Germany for the breed and meat production still represents a disputed topic under the criterion of the animal's welfare. Above all critics state that the frequently wet-cold weather in Germany impairs the well-being and health of the animals. So far however there are just a few scientifically documented data about requirements for housing conditions of ostriches in Central Europe and thus hardly answers whether housing in Germany is possible under the criteria of the animal's welfare. This study tried to evaluate ostrich housing under South German climatic conditions (Rhine level), on the basis of behavioral observations of breeding ostriches. The use of the stable and the influence of different climatic parameters on the behavior were considered. In addition the behavior of 18 adult animals in 5 breeding groups from January to December 2002 was observed. Parallel various climatic data were raised. The housing of the animals took place in open stables with unrestricted pasture possibility. The ostriches reacted in their behavior to different climatic conditions. Particularly at cold weather and adverse soil conditions they used the open stable increasingly as weather protection. In addition, with increased wind velocities the animals spent more time in the stables. The daily amount of precipitation showed no influence on the frequency or duration of the stable use. Rainfall did not animate the animals to look for protection within the stable, but more to set itself on the ground in the external enclosure. The locomotion activity of the animals was strongly in dependence to the reproduction time and the territorial behavior and therefore highest in spring. On cold days the animals performed their reproduction behavior mainly in the stable. For the comfort behaviour distinct weather dependence was seen particularly for sand bathing. Warm temperatures and dry sand were the preconditions for it. Regarding the results it seems, that with the conditions existing on the examined farm, housing of ostriches under respect of animal welfare in Germany is possible. New regulations are to be demanded, adjusted to the newest level of knowledge about ostrich husbandry, with requirements for care, support, accommodation and nutrition of the animals as well as about the qualification of the owners. An occasional hobby animal husbandry limited to few single ostriches is to be rejected. Further scientific investigations at other farms, possibly also under variable climatic conditions are however necessary.

Analog states of 7He observed via the 6He(p,n) reaction.

Isobaric analog states of 7He have been investigated by a novel technique involving the observation of the resonant yield of neutrons from the 6He(p,n) reaction in coincidence with gamma rays from the decay of the (0(+),T=1) state in 6Li. The gamma rays provide a clean signature for the isospin-conserving neutron decay of the low-lying isobaric analog resonances. It is conclusively shown that the analog of the recently observed low-lying spin-orbit partner of the 7He ground state does not exist. Evidence is presented that this state lies at much higher energies, in agreement with microscopic calculations.

N=82 shell quenching of the classical r-process "waiting-point" nucleus 130Cd.

First beta- and gamma-spectroscopic decay studies of the N=82 r-process "waiting-point" nuclide 130Cd have been performed at CERN/ISOLDE using the highest achievable isotopic selectivity. Several nuclear-physics surprises have been discovered. The first one is the unanticipatedly high energy of 2.12 MeV for the [pi g(9/2) multiply sign in circle nu g(7/2)] 1(+) level in 130In, which is fed by the main Gamow-Teller transition. The second surprise is the rather high Q(beta) value of 8.34 MeV, which is in agreement only with recent mass models that include the phenomenon of N=82 shell quenching. Possible implications of these new results on the formation of the A approximately 130 r-process abundance peak are presented.

First On-line beta-NMR on oriented nuclei: magnetic dipole moments of the (nup(1/2))(-1) 1/2(-) ground state in 67Ni and (pip(3/2))(+1) 3/2(-) ground state in 69Cu

The first fully on-line use of the angular distribution of beta emission in detection of NMR of nuclei oriented at low temperatures is reported. The magnetic moments of the single valence particle, intermediate mass, isotopes 67Ni(nup(-1)(1/2);1/2(-)) and 69Cu(pip(1)(3/2);3/2(-)) are measured to be +0.601(5) &mgr;(N) and +2.84(1) &mgr;(N), respectively, revealing only a small deviation from the neutron p(1/2) single-particle value in the former and a large deviation from the proton p(3/2) single-particle value in the latter. Quantitative interpretation is given in terms of core polarization and meson-exchange currents.