Search results for "Nuclear structure"
showing 10 items of 401 documents
Conversion coefficients of the isomeric state in 72Br
2010
In order to determine the Gamow‐Teller strength distribution for the N = Z nucleus 72Kr an experiment was performed with a Total Absorption Gamma Spectrometer. To fully accomplish this task it is crucial to determine the multipolarity of the low energy transitions as the spin‐parity of the daughter ground state has been debated. This is done by experimental determination of the conversion coefficients. Preliminary results for the multipolarity and conversion coefficients of the transition connecting the isomeric state at 101 keV with the 72Br ground state are presented.
Decay properties of exoticN≃28 S and Cl nuclei and theCa48/46Ca abundance ratio
1993
Beta-decay half-lives and \ensuremath{\beta}-delayed neutron-emission probabilities of the very neutron-rich nuclei $^{44}\mathrm{S}$ and $^{45--47}\mathrm{Cl}$ have been measured. These isotopes, which lie at or close to the N=28 magic shell, were produced in interactions of a 60 MeV/u $^{48}\mathrm{Ca}$ beam from GANIL (Grand Acc\'el\'erateur National d'Ions Lourds) with a $^{64}\mathrm{Ni}$ target, and were separated by the doubly achromatic spectrometer LISE (Ligne d'Ions Super Epluch\'es). Their decay was studied by a \ensuremath{\beta}-n time correlation measurement. The results are compared to recent model predictions and indicate a rapid weakening of the N=28 shell effect below $_{2…
DETERMINATION OF NUCLEAR GROUND STATE PROPERTIES FAR FROM STABILITY BY OPTICAL PUMPING
1973
The possibilities of determining nuclear spin, moments and variation in charge volume by optical pumping of on line masseparated isotopes are described for the example of the isotopic chain lY1Hg-205Hg. The variation in nuclear charge volume (6 ) along this chain and in particular its abrupt change for the lightest Hg-isotopes, indicating a phase transition in nuclear structure, are discussed. 1. Introduction. - This talk is based on expe- riments (I), (2), (3) performed recently by a visiting team (*) at the ISOLDE facility at CERN with the members : J. Bonn, G. Huber, H.-J. Kluge, U. Kopf, L. Kugler, J. Rodriguez, and E. W. Otten. The investigation of the hyperfine structure (hfs) and iso…
Spectroscopic studies with the PRISMA-CLARA set-up
2010
The large solid angle magnetic spectrometer for heavy ions PRISMA, installed at Laboratori Nazionali di Legnaro (LNL), was operated up to the end of March 2008 in conjunction with the highly efficient CLARA set-up. It allowed to carry out nuclear structure and reaction mechanism studies in several mass regions of the nuclide chart. Results obtained in the vicinity of the island of inversion and for the heavy iron and chromium isotopes are presented in this contribution. The status of the new focal plane detectors specifically designed for light ions and slow moving heavy ions is also reported.
Ion-optical layout of a powerful next-generation pre-separator for in-flight separation of relativistic rare isotopes
2006
Abstract Rare isotope beams can be efficiently produced at relativistic energies via projectile fragmentation and projectile fission. Magnetic rigidity analysis in combination with atomic energy loss ( Bρ –Δ E – Bρ method) in profiled matter placed at dispersive focal planes represents the tool for spatial separation in flight. The next-generation in-flight separators at high energies will consist of multiple degrader stages to provide intense monoisotopic fragment beams of all elements up to uranium. The pre-separator layout with the first degrader system holds many technical challenges, e.g. to handle the high-power primary beams characterized by a large range in time structure, from a DC…
The impact of the properties of the heaviest elements on the chemical and physical sciences
2012
Abstract The unique role of the heaviest elements in chemical and physical sciences is discussed. With the actinide series (Z = 90-103) and the superactinide series (Z = 122-155), the heaviest elements have significantly shaped the architecture of the Periodic Table of the elements. Relativistic effects in the electron shells of the heaviest elements change the chemical properties in a given group in a non-linear fashion. Relativistically stabilized sub-shell closures give rise to a new category of elements in the Periodic Table: volatile metals. The prototype for this property is element 114 which, due to the relativistic stabilization of its 7s2 7p2 1/2 electron configuration, is volatile…
Recent Results from In-Beam Studies of Very Neutron-Deficient Nuclei
2000
Nuclear structure of very neutron deficient Z ≈82 nuclei and very heavy nuclei has been studied by employing in-beam γ-ray spectroscopic methods involving recoil-gating and recoil-decay tagging (RDT) methods.
About the Reliability of Extrapolation of Nuclear Structure Data for r-process Calculations
2002
Gross decay properties are the nuclear part of the input for calculations of elemental abundances. They depend, sometimes very sensitively, on details of nuclear structure. Models for predictions of nuclear masses and shapes have to be used for isotopes very far from stability. The reliability of extrapolations far from experimentally reachable nuclei is, however, not always granted due to singularities in the nuclear landscape. We review data on the region of the neutron-rich isotopes near A = 100, which is a region of especially dramatic changes.
Proton-Rich Light Nuclei
1989
A basic question for a given element of how few or how many neutrons can be contained in its nucleus and still result in a “bound” system, and the resulting consequences on our present concept of nuclear structure, have been the focus of much recent research on highly unstable nuclei. It is only during the last several years that the limit of nuclear stability has been reached in a few areas of the nuclear chart. Except among the lightest elements, knowledge of the limit on the neutron-excess side is still beyond our experimental capability. For the heavier elements, the gap between the most neutron-rich isotope known and the isotope which is predicted to define the neutron drip-line more o…
Electron Scattering Experiments on Light Nuclei
2020
In this contribution we discuss double-polarised quasi-elastic electron scattering from \({}^{3}\mathrm {He}\) and \({}^{12}\mathrm {C}\). For these nuclei precise data from recent experiments at Jefferson Lab and Mainz have become available, accompanied by a very strong theoretical effort dedicated to understanding these nuclei. The double polarisation experiments presented here offer insight into some of the details of the nuclear structure that could not be accessed by traditional cross-section measurements. The new experimental results show only rough agreement with the calculations and indicate that we do not yet fully understand the structure of these nuclei and nucleon dynamics insid…