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The stable Cd isotopes have long been used as paradigms for spherical vibrational motion. Extensive investigations with in‐beam γ spectroscopy have resulted in very‐well‐established level schemes, including many lifetimes or lifetime limits. A programme has been initiated to complement these studies with very‐high‐statistics β decay using the 8π spectrometer at the TRIUMF radioactive beam facility. The decays of 112In and 112Ag have been studied with an emphasis on the observation of, or the placement of stringent limits on, low‐energy branches between potential multi‐phonon levels. A lack of suitable 0+ or 2+ three‐phonon candidates has been revealed. Further, the sum of the B(E2) strength from spin 0+ and 2+ states up to 3 MeV in excitation energy to the assigned two‐phonon levels falls far short of the harmonic‐vibrational expectations. This lack of strength points to the failing of collective models based on vibrational phonon structures.

The double beta decay experiment NEMO‐3 has compleated data taking in January 2011. The aim of the experiment is to search for the neutrinoless double beta decay and investigate the two‐neutrino double beta decay in seven different isotopes (100Mo, 82Se, 116Cd, 150Nd, 96Zr, 48Ca and 130Te). After analysis of the most part of available data corresponding to 4.5 yr no evidence for 0νββ decay in 100Mo and 82Se is found. The half‐life limits at 90% C.L. are 1.0×1024 yr and 3.2×1023 yr respectively. The two‐neutrino decay half live values were precisely measured for all investigated isotopes.

The compression-mode isoscalar giant monopole resonance (ISGMR) has been studied in the Sn, Cd and Pb isotopes using inelastic scattering of 400 MeV {alpha}-particles at extreme forward angles, including 0 deg. We have obtained completely 'background-free' inelastic-scattering spectra for the Sn, Cd, and Pb isotopes for a wide angular and excitation-energy range. The various giant resonances excited with different transferred angular momenta were extracted by a multipole-decomposition analysis (MDA). It was found that the centroid energies of the ISGMR in Sn isotopes are significantly lower than the theoretical predictions. The K{sub {tau}} in the empirical expression for the nuclear incompressibility has been determined to be K{sub {tau}} = -550{+-}100 MeV for the Sn isotopes. The extracted value for the Cd isotopes is K{sub {tau}} = -480{+-}100 MeV. These numbers are consistent with values of K{sub {tau}} = -370{+-}120 MeV obtained from an analysis of the isotopic transport ratios in medium-energy heavy-ion reactions, K{sub {tau}} -500{sub -100}{sup +120} MeV obtained from constraints placed by neutron-skin data from anti-protonic atoms across the mass table, and K{sub {tau}} = -500{+-}50 MeV obtained from theoretical calculations using different Skyrme interactions and relativistic mean field (RMF) Lagrangians. Stringent constraints on interactions employed in nuclear structuremore » calculations are obtained on the basis of the experimentally determined values for K{sub {infinity}} and K{sub {tau}}. These parameters constrain as well the equation of state (EOS) of nuclear matter. However, a significant discrepancy still remains. The ISGMR positions in Sn and Cd isotopes are systematically lower than the predictions obtained on basis of determined from the ISGMR in {sup 208}Pb. This raises the question ''Why are Sn and Cd nuclei so soft?''. For a clue to solve the problem, we discuss the preliminary results on the exact positions of the ISGMR in {sup 204,206,208}Pb.« less

The astrophysical origin of a p-nucleus {sup 115}Sn has remained still an open question. The nucleus {sup 115}Sn may be produced by a weak branch of the s-process through a beta-unstable isomer in {sup 113}Cd. However, a neutron capture cross-section to this isomer has not been measured with high accuracy at any energy. A neutron capture cross-section for the {sup 112}Cd(n,gamma){sup 113}Cd{sup m} reaction has been measured with neutrons provided from a nuclear reactor. The nucleus {sup 115}Sn may be produced by a nucleosynthesis flow through {sup 113}Cd{sup m} in the s-process. We have obtained the thermal neutron capture cross-section of 0.028+-0.009[b] and the resonance integral of 1.1+-0.3[b] using a cadmium difference method. The cross-section ratio of the isomer to the ground state has been calculated as a function of the incident neutron energy, E, by using a statistical model. The calculated ratios are almost constant over a wide range of E

The decay properties of rp‐process nuclei in the vicinity of 100Sn have been studied at the National Superconducting Cyclotron Laboratory (NSCL). The measured β‐decay half‐life for 100Sn is 0.55−0.31+0.70 s, in agreement with a previous measurement. In 98In, the β‐decay of the ground state plus that of a long lived isomer were observed with half‐lives of 47(13) ms and 0.66(40) s respectively. The half‐life of 96Cd, measured for the first time, is 1.03−0.21+0.24 s; however, the existence of a predicted isomeric state in this nucleus could not be confirmed. Additionally, a gamma cascade de‐exciting a μ‐isomer in the odd‐odd nucleus 96Ag was observed. The implications of the measured half‐life of 96Cd on the calculated rp‐process final abundances are discussed.

We report on the ``safe'' Coulomb excitation of neutron-rich Cd, Xe, and Ba isotopes in the vicinity of the doubly-magic nucleus 132Sn. The radioactive nuclei have been produced by ISOLDE at CERN and postaccelerated by the REX-ISOLDE facility. The gamma-decay of excited states has been detected by the MINIBALL array. The presented preliminary results for the B(E2) values are consistent with expectations from phenomenological systematics and will be compared with theoretical calculations. Book subtitle: FINUSTAR 2 ispartof: pages:84-88 ispartof: AIP Conference Proceedings vol:1012 issue:1 pages:84-88 ispartof: Frontiers in NUclear STructure, Astrophysics and Reactions: FINUSTAR location:Kos, Greece date:10 Sep - 14 Sep 2007 status: published

The simulation of p‐process nucleosynthesis requires thousands of reaction rates. These rates are typically calculated with the statistical Hauser Feshbach Model (HF‐Model) which depends critically on the reliability of the optical nucleus potential. In particular, the predicted (α,γ) cross sections at low energies (below 20 MeV) are sensitive to the choice of the alpha potential. Dscrepancies have been observed between the experimental cross sections and the theoretical values (NON‐SMOKER). Currently, only a few α‐induced reaction rates have been measured. To explore the trend 106Cd(α,γ)110Sn and 112Sn(α,γ)116Te cross sections were measured at the Notre Dame FN Tandem accelerator. First results are presented and discussed.

We present some measurements of nuclear fluorescence which were made while exploring the potential of a unique source of very hard x‐rays which was installed at ESRF until recently. It produced radiation of energies up to 1MeV. In this range there are many nuclear resonances, and so we made a small survey of some plausible candidates to see if they could indeed be excited using this source. Along with short‐lived resonances, we were also able to indirectly populate long‐lived isomeric states in several nuclei. Thus, simply exposing the samples to the white beam for a period of time caused them to be activated. The samples could them be removed from the beam and their emissions observed using an energy‐resolving detector. Isomeric states in isotopes of indium, cadmium and silver were excited and their subsequent decay observed.

Using a laser‐induced fluorescence method a detailed analysis of profiles of the 114Cd 326.1 nm line perturbed by neon was performed which revealed deviations from the ordinary Voigt profile. These deviations are shown to be consistent with fits of experimental profiles to an asymmetric Voigt profile. Coefficients of the pressure broadening, shift and collision‐time asymmetry are determined and compared with those calculated in the adiabatic approximation for different interaction potentials.

Results on 103–107In strength function measurements are presented. The domination of the core (πg9/2)8 over the valence proton decay is confirmed. Contribution of a βp decay channel to the total β strength function of 0.5% and 43% for 102In and 100In, respectively, is expected based on the BGT systematics, available βp spectra and statistical model calculations.

Many of the {sub 48}Cd nuclei are good examples of U(5) or vibrational nuclei. Like the {sub 50}Sn nuclei and others in the region, states exist which are interpreted in terms of the excitation of a pair of protons across the shell gap (intruders). The features of the comparatively well-understood Cd nuclei will be considered and compared with the{sub 52}Te nuclei where intruders have not been identified experimentally and problems exist with the U(5) interpretation.

The production of isotopes near 100Sn has been investigated by using on-line mass separation of evaporation residues produced by heavy-ion induced complete fusion reactions. We measured β-delayed protons and γ-rays, deduced the mass-separated beam intensities for 99Cd, 100In, 101Sn and 102In, and determined the corresponding production cross-sections σ for 58Ni+58Ni reactions followed by emission of nuclear clusters, and for 58Ni+50Cr reactions accompanied by emission of protons, neutrons and α particles. The results indicate that the σ values for reactions followed by emission of clusters are comparable with those for reactions proceeding through light particle emission. Due to recoil-loss effects in on-line mass separation, the former mechanism is less suitable than the latter one for producing such neutron-deficient nuclei in this kind of experiments.

In the present contribution, we concentrate on the specific effects the proton‐neutron force implies when studying low‐energy nuclear structure phenomena. We discuss various cases where a proton‐neutron quadrupole component can lead to systematic changes in the nuclear structure: NπNv scaling in open‐shell nuclei and low‐lying 0+ intruder excitations near closed shells. We moreover describe the influence of the proton‐neutron force in a dynamic way on the nuclear radius in nuclei near closed shells using a shell‐model and a collective model (vibrations) approach.

Using on-line separation combined with γ-ray and conversion-electron spectroscopy, decay properties of neutron-deficient isotopes were measured near 100Sn. The QEC values, the excitation energies of 1+ levels, and the strength for 0+→1+ Gamow-Teller β transitions, as obtained for the decay of the even-even nuclides 94Ru, 96–100Pd, 100–104Cd, and 104–110Sn, are compared with predictions from shell-model calculations including deformation, pairing and core-polarization effects. The quenching of the Gamow-Teller strength, as deduced from this comparison, is presented. Furthermore, low-lying levels in 104In are discussed with particular emphasis on a possibility of observing spin-mixing.

The nuclear analog of the ruby laser is shown in Fig. 1. It embodies the simplest concepts for a gamma‐ray laser. Not surprisingly, the greatest rate of progress has occurred in this direction. Studies aimed at upgrading the nuclear database have yielded a singularly useful technique for the calibration of large pulsed bremsstrahlung sources used for pumping in the region from 150 keV to 1.3 MeV. In addition, experiments utilizing bremsstrahlung from a 6 MeV linear accelerator have indicated the possibility of accessing the broad octupole states above 2 MeV in 111Cd, 113In and 115In. Effective integrated cross sections (πbaboσoΓ/2) on the order of 104 cm2 keV were observed. Finally the upconversion pumping, shown schematically in Fig. 2, of the first of 29 potential candidate materials for a gamma‐ray laser was reported.