R. Schwengner

Development of segmented Ge detectors for future γ-ray arrays

The EUROBALL Cluster detector is composed of seven encapsulated Ge detectors in a common cryostat with a total volume of 2000 ccm of HP Gemanium. The development and the performance of the Cluster detector is summarized. Up to six Cluster detectors were used in pre-EUROBALL experiments at the S-DALINAC Darmstadt, at the tandem-postaccelerator facility of the MPI-K Heidelberg and at the UNILAC at GSI. Examples of these experiments - the excitation of dipole modes with (γ, γ′)-reactions and the first coincidence spectroscopy of the N=Z-nucleus 68Se with a CLUSTER Cube - are discussed. The development of segmented encapsulated Ge detectors for a MINIBALL at the radioactive beam facility REX-ISOLDE has been launched. The status of the project is presented.

Pygmy dipole strength in Zr 90

The dipole response of the

Photon data shed new light upon the GDR spreading width in heavy nuclei

N=50

Fine structure of the E1 response in 140Ce below the particle threshold

nucleus

Test of Compton camera components for prompt gamma imaging at the ELBE bremsstrahlung beam

^{90}\mathrm{Zr}

The first candidate for chiral nuclei in the A~80 mass region: 80Br

was studied in photon-scattering experiments at the electron linear accelerator ELBE with bremsstrahlung produced at kinetic electron energies of 7.9, 9.0, and 13.2 MeV. We identified 189 levels up to an excitation energy of 12.9 MeV. Statistical methods were applied to estimate intensities of inelastic transitions and to correct the intensities of the ground-state transitions for their branching ratios. In this way we derived the photoabsorption cross section up to the neutron-separation energy. This cross section matches well the photoabsorption cross section obtained from (

Isomerism in 96Ag and non-yrast levels in 96Pd and 95Rh, studied in β decay

\ensuremath{\gamma}

Two-phonon J = 1 states in even-mass Te isotopes with A = 122–130☆

,

Change of the dipole strength distributions between the neighbouring γ-soft nuclei 194Pt and 196Pt☆

n

Nuclear deformation and neutron excess as competing effects for dipole strength in the pygmy region.

) data and thus provides information about the extension of the dipole-strength distribution toward energies below the neutron-separation energy. An enhancement of