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The emerging experimental program for photofission research at ELI-NP is briefly summarized. GEANT4 Monte Carlo simulations, providing estimates of the collimated beam profile of the ELI-NP gamma beam: beam energy bandwidth and beam spot dimensions, the required target dimensions, and fission fragment emission rates, their mass and energy distributions, have been reported, which ensure the feasibility of high-resolution studies of the multiple-humped fission barrier. A spectrometer consisting of four ionization chambers coupled to Si strip detectors, called ELI-BIC, is being developed for these measurements, and is briefly discussed. [ABSTRACT FROM AUTHOR]

The brilliant gamma beam at the future Extreme Light Infrastructure - Nuclear Physics (ELI-NP) facility will be used to generate a beam of exotic neutron-rich isotopes via photofission ofactinide targets. We present simulations with the Geant4 toolkit ofthe photofission process for the design and optimization ofthe expected performance parameters ofthe Cryogenic Stopping Cell (CSC). The CSC will be used to extract the photofission fragments into the secondary beam of about 106 ions/s. We propose an experimental program to study refractory neutron-rich isotopes. [ABSTRACT FROM AUTHOR]

The gyromagnetic factor of the isomeric state of 43S has been measured using the Time Dependent Perturbed Angular Distribution (TDPAD) technique. The isomer was produced and spin aligned via the fragmentation of a 60 AMeV 48Ca beam at the GANIL facility. The deduced magnetic moment confirms the 7/2- spin/parity of the isomeric state and shows, for the first time, the intruder nature of the ground state. Comparison of the experimental values with Shell Model and mean-field based calculations were performed revealing a pronounced ground state deformation and a quasi-spherical isomeric state. A new isomeric state has been observed in the 42P. [ABSTRACT FROM AUTHOR]

Spectroscopic quadrupole moment measurements for high-spin isomeric states in 192,193,194Pb nuclei have been performed by the time-differential perturbed γ-ray angular distribution method. The quadrupole moments of the isomers described by quasineutron configurations in neutron-deficient Pb nuclei are well reproduced by the pairing plus quadrupole model, which predicts for these states a very small prolate deformation β2 ≈0.02. The quadrupole moment of the 11- isomeric state in 192Pb involving the π(3s1/2-2 1h9/2 1i13/2) configuration corresponds to a deformation β2=-0.11(1). The quadrupole moments of the proton intruder states in Pb nuclei are compared with theoretical predictions of tilted-axis cranking, mean-field and interacting boson models. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The application of the Time Dependent Perturbed Angular Distribution (TDPAD) method to study isomeric states produced and oriented in projectile-fragmentation reactions provides the opportunity to perform nuclear-moment measurements in a wide range of neutron-rich nuclei, unaccessible by other means. An absolute necessity for the application of the TDPAD technique is a spin-aligned ensemble of nuclei. The preliminary results from a recent application of this method on 61mFe and 54mFe at GANIL, Caen, France showed that a significant increase of the amount of the observed alignment, compared to our previous measurement on 67mNi and 69mCu, can be obtained. Some experimental details, concerning the conservation of the reaction obtained alignment, are discussed. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]

Three, possibly four, regularly spaced rotational bands with large dynamical moments of inertia, which are consistent with known superdeformed bands in the Lu/Hf region, have been identified in [sup 174]Hf. The states were populated in the [sup 130]Te([sup 48]Ca,4n) reaction at a beam energy of 194 MeV. The Gammasphere array detected the emitted gamma radiation. Ultimate cranker calculations predict substantial triaxial deformation (γ ≈ 17°) for highly deformed [sup 174]Hf structures. However, [sup 174]Hf is eight neutrons away from the previously established N = 94 triaxial superdeformed shell gap. Shell gaps at N = 100 and 106 with γ ≥ 15° are observed when ε[sub 2] ≈ 0.45, which may be responsible for the predicted TSD minima in [sup 174]Hf. [ABSTRACT FROM AUTHOR]

We report on the first application of the TDPAD method to measure the g factor of neutron-rich isomeric states, produced and aligned in a projectile fragmentation reaction. The feasibility of similar measurement opens up a new, unexplored region of the nuclear chart for studies of the magnetic moments of microsecond isomers. Nuclei around [sup 68]Ni were produced following the fragmentation of 61.6 MeV/u [sup 76]Ge on a 145 mg/cm² Be target. The isotopes of interest were selected using the LISE spectrometer at GANIL, Caen, France, and were implanted in a high purity Cu foil fixed between the poles of an electromagnet. Two Ge Clover detectors, positioned in a plane perpendicular to the holding magnetic field, were used to observe the rotation of the nuclear spin ensemble and to derive the experimental R(t) function. The experimental result for the isomer in [sup 67]Ni (Jπ = 9/2[sup +], T[sub ½] = 13.3 µs, E[sub x] = 1007 keV), g = 0.125(6), is presented herein and is also compared to the theoretical expectations. [ABSTRACT FROM AUTHOR]

Four regularly spaced rotational bands with large dynamical moments of inertia, which are consistent with known superdeformed bands in the Lu/Hf region, have been identified in [SUP174]Hf. The states were populated in the [SUP130]Te([SUP48]Ca,4n) reaction ar a beam energy of 194 MeV. The Gammasphere array detected the emitted gamma radiation. Ultimate cranker calculations predict substantial triaxial deformation (&b.gamma; ± 17°) for highly deformed [SUP174]Hf structures. However, [SUP174]Hf is eight neutrons away from the previously established N = 94 triaxial superdeformed shell gap. Shell gaps at N = 100 and 106 with &b.gamma; ≤ 15° are observed when &b.epsi;2 ≈ 0.45, which may be responsible for the predicted TSD minima in [SUP174]Hf. [ABSTRACT FROM AUTHOR]

The spectroscopic quadrupole moments of the 11[sup -] isomers in [sup 194]Pb and [sup 196]Pb have been measured by applying the Level Mixing Spectroscopy technique. These isomers have the π(s[sub 1/2][SUP ARRANGE="STAGGER"]-2]h[sub 9/2]i[sub 13/2]) proton configuration. The implications of these results for the influence of the intruder character of the isomers on their deformation is given. We will especially focus on a simple 2-dimensional model, taking into account the coupling of the valence nucleons with the vibrations of the underlying core, which gives theoretical insight in the obtained experimental results for the quadrupole moments of the 11[sup -] isomers. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Recently, an intense experimental effort has been devoted to the search of empirical proofs of critical-point symmetries in nuclear structure. These symmetries describe shape-phase transitions and provide parameter-free predictions (up to over-all scale factors) for excitation spectra and B(E2) values. This contribution reports on recent plunger-lifetime measurements ON 102Pd carried out at LNL, Legnaro, with the Cologne plunger apparatus coupled to the GASP spectrometer and using the 92Zr(13C,3n)102Pd reaction at 48 MeV. According to the results of our measurements, 102Pd is so far the best known paradigm of the E(5) critical-point symmetry. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]

The lifetimes of the lowest collective yrast and non-yrast states in 128Xe were measured in a Coulomb excitation experiment using the recoil distance method (RDM) in inverse kinematics. Hereby, the Cologne plunger apparatus was employed together with the JUROGAM spectrometer. Excited states in 128Xe were populated using a 128Xe beam impinging on a natFe target with E(128Xe)≈525 MeV. Recoils were detected by means of an array of solar cells placed at forward angles. Recoil-gated γ-spectra were measured at different plunger distances. [ABSTRACT FROM AUTHOR]