Yorick Blumenfeld
(CERN-CERN-CERN)
17/11/2008, 14:00
Welcome of participants and brief news items from ISOLDE.
Dr
Magdalena Kowalska
(CERN)
17/11/2008, 14:40
The ISOLDE mass-spectrometer Isoltrap has recently successfully addressed a number of scientific highlights across the entire nuclear chart, among others: the question of proton-halo character of 17Ne, and the ``restoration'' of the 132,134Sn and 80,81Zn shell closures, of great relevance for the astrophysical r process. The latest results include masses of neutron-rich Ag and Cd isotopes...
Simon Van Gorp
(Inst. voor Kern- en Stralingsfysica - Katholieke Universiteit Le)
17/11/2008, 15:10
S. van Gorp, M. Tandecki, E Traykov, F. Wauters, N. Severijns - Leuven
M. Beck, P. Friedag, C. Weinheimer - Muenster
V. Kozlov – KFA Karlsruhe
A. Herlert, F. Wenander, P. Delahaye – ISOLDE/CERN
The WITCH set-up (Weak Interaction Trap for Charged Particles) combines a double Penning trap system to store radioactive ions and a retardation spectrometer to probe the energy of the daughter...
Mr
Dennis Neidherr
(Institut fur Physik - Johannes Gutenberg-Universitat Mainz)
17/11/2008, 15:30
In August 2008 the masses of neutron rich Xe and Rn isotopes were measured at the tandem Penning trap mass spectrometer ISOLTRAP with a relative mass precision down to a 1x10-8. During this online period the masses of 143-146Xe and 223-229Rn were measured, many of them for the first time directly. In addition the short-lived nuclide 229Rn has been observed for the very first time and aside of...
Dr
Georgi Georgiev
(CSNSM, Orsay, France)
17/11/2008, 16:20
The possibility of obtaining spin-polarized nuclei is an essential asset for performing nuclear physics experiments with radioactive nuclei. The nuclear magnetic-dipole and electric quadrupole moments are of key importance for the profound understanding of the nuclear structure, especially when one moves away from the stability line. Obtaining an ensemble of polarized nuclei is a primary...
Lara Risegari
(Cen. de Spect. Nucl. & Spect. Masse (CSNSM)-91405 Orsay Campus-France)
17/11/2008, 16:50
In a recent experiment at the NICOLE on-line nuclear orientation facility, gamma decay anisotropy and nuclear magnetic resonance measurements were made on Hf isotopes. A HfF3 beam was used to implant separated Hf isotopes into a magnetized pure iron foil cooled to temperatures down to 15 millikelvin.
NMR/ON resonance was observed in the 37/2- K-isomer of 177Hf and angular distributions...
Nathal Severijns
(Kath. Univ. Leuven)
17/11/2008, 17:10
A new method to determine the beta asymmetry parameter in the decay of polarized nuclei was developed. The nuclei are polarized with the low temperature nuclear orientation method and beta particles are observed with Si and Ge detectors operating inside the 4 Kelvin part of the nuclear orientation set-up. Essential to the method is further the newly developed Geant4 based Monte Carlo code for...
J. N. Goncalves
(Universidade de Aveiro, Physics Department and CICECO, Aveiro 3810-193, Portugal)
17/11/2008, 17:30
We report on perturbed angular correlation (PAC) spectroscopy studies on magnetic compounds BaMnO3 and MnAs. Hyperfine parameters, e.g., the local Electric Field Gradient and Hyperfine Magnetic Field were measured by using the isotope probes 111Cd in BaMnO3 and 77Se in MnAs. MnAs was measured in a short range of temperatures near the first order magneto-structural transition at T=45 C. For the...
Dr
Emma de Ona Wilhelmi
(APC)
17/11/2008, 17:50
Over the past few years, very-high-energy gamma-ray astronomy has
emerged as a truly observational discipline, with many detected sources
representing different galactic and extragalactic source
populations-supernova remnants, pulsar wind nebulae, giant molecular
clouds, star formation regions, compact binary systems, and active
galactic nuclei. The H.E.S.S. array of imaging...
Dr
Valentine Fedosseev
(CERN)
18/11/2008, 09:00
At ISOLDE RILIS the resonance ionization of isotopes is provided by high pulse rate dye lasers. Till 2008 the dye lasers were pumped by copper vapor lasers built in Russia and delivered to CERN on 1989. With the progress in laser technology it became possible to replace the copper vapor lasers by contemporary solid state lasers. In spring 2008 a 100W Nd:YAG laser has been installed at RILIS....
Van De Walle Jarno
(CERN, ISOLDE)
18/11/2008, 11:20
The Miniball germanium array has been in use at REX-ISOLDE for more than six years now. Over these years, Coulomb excitation experiments have been performed on a variety of isotopes ranging from Mg (Z=12) to Rn (Z=86). Many of these Coulomb excitation experiments aim at the study of shell evolution far off the line of beta stability by measuring transition probabilities between low lying...
Dr
Andrew Robinson
(University of York)
18/11/2008, 11:50
One of the remarkable properties of the nucleus is its ability to minimise its energy by adopting different deformed nuclear shapes. In some cases, this can lead to competing minima very close together. This phenomena has been widely tracked through the neutron-deficient lead, mercury and platinum isotopes, where the shape coexistence has been discussed in terms of intruder states based on...
Mr
Andrew Petts
(University of Liverpool)
18/11/2008, 12:10
In light, even mass Hg isotopes, a weakly deformed oblate ground state band is found to coexist with a more deformed prolate band. To investigate the origin and evolution of shape coexistence in the N = 102-108 mid shell region Coulomb excitation measurements of 182,184,186,188Hg were performed at REX-ISOLDE using the MINIBALL detector array. The radioactive Hg beams were provided by ISOLDE...
Dr
Aaron Hurst
(Lawrence Livermore National Laboratory)
18/11/2008, 12:30
The wave-function composition for the low-lying states in 29Na was explored by measuring their electromagnetic properties using the Coulomb-excitation technique. A beam of radioactive 29Na ions, postaccelerated to 70 MeV using ISAC-II at TRIUMF, bombarded a 110Pd target with a rate of up to 600 particles per second. Six segmented clover detectors of the TIGRESS gamma-ray spectrometer were...
Michael Thoennessen
(Michigan State University)
18/11/2008, 14:10
The discovery of new isotopes is the first step in the exploration of the properties of the most exotic nuclei. At the NSCL we applied different techniques to produce and identify new isotopes. With the Modular Neutron Array (MonA) it is possible to study the spectroscopy of nuclei close to and even beyond the neutron dripline.
Dr
Haik Simon
(Gesellschaft für Schwerionenforschung mbH (GSI))
18/11/2008, 14:40
The light nuclei region in the chart of nuclei is recently subject to intense theoretical studies starting from ab initio calculations or using phenomenologic
few body approaches. All of these have in common, that they reveil or explore an intrinsic property of these systems: the appearance of strong clustering effects, showing the importance of residual interactions in a mean field picture. ...
Elisabeth Tengborn
(Chalmers University of Technology)
18/11/2008, 15:10
The post-accelerator for radioactive beams, REX-ISOLDE, provides beams of energies of 0.3-3.1 MeV/u. Thus, it enables the study of the majority of the nuclides available at CERN-ISOLDE through low-energy reactions. This opens the possibility to use Coulomb excitation, fusion and transfer reactions as spectroscopic tools for studying exotic nuclei.
Exotic light nuclei are being studied...
Severijns Nathal
(Instituut voor Kern- en Stralingsfysica - KU-University of Leuve)
18/11/2008, 17:00
Recently, a complete analysis of the half-lives and branching ratios for the beta transitions between isospin T = 1/2 isospin doublets in mirror nuclei, together with detailed calculations of the radiative, isospin-symmetry breaking and nuclear structure corrections, have provided the corrected Ft-values for these mirror transitions up to A = 45.
Combining these Ft-values with results from...
Prof.
Alexandrina Petrovici
(National Institute of Physics and Nuclear Engineering (IFIN-HH)-)
18/11/2008, 17:30
We present a variational treatment of the effects of the isospin-symmetry
breaking on the superallowed Fermi $\beta$ decay of medium mass nuclei dominated
by shape coexistence and mixing allowing for a simultaneous description of the
analog as well as significant non-analog branches.
The Gamow-Teller strength distributions and the half-lives for the beta decay of
the ground state and the...
Jens Ketelaer
(Universität Mainz, Institut für Physik, Staudinger Weg 7, D-55128 Mainz, Germany)
18/11/2008, 17:50
Nuclear masses are fundamental quantities in nature, reflecting the binding energy of the nucleons. In particular, experimentally determined masses of heavy nuclides provide new information on nuclear structure and test theoretical mass models in this region of the nuclear chart [1,2]. Masses of a few nobelium isotopes have been recently determined by SHIPTRAP (GSI, Darmstadt, Germany)....
Prof.
Hanns-Ulrich Habermeier
(Max-Planck-Institute-FKF)
19/11/2008, 09:00
Mastering the technological challenges in semiconductor thin film physics has been the baseline for the microelectronic revolution in the second half of the last century. Similarly, complex oxides with strong electron correlation, characterized by their plethora of functionalities - ranging from superconductivity to ferromagnetism - are expected to play a similar role in electronics in this...
Lino Miguel Da Costa Pereira
(Univ. do Porto-IFIMUP-IN)
19/11/2008, 09:30
Magnetically doped semiconductors (dilute magnetic semiconductors - DMS) are seen as strong candidates to make use of the carriers spin in spintronic devices. Latest results of both experiment and theory are driving the research focus towards wide-gap semiconductors doped with 3d transition metals. However, any attempt to understand the room temperature ferromagnetism observed in these...
Joao Martins Correia
(UFA, Instituto Tecnológico e Nuclear)
19/11/2008, 09:50
This talk reports on the results from the electron emission channeling on-line run of the ECSLI collaboration, which took place during this year’s Mn beam time in September. We were able to determine the lattice sites of implanted 56Mn (2.6 h) in ZnO, Ge and GaAs, and of 61Co (1.6h) in GaN during the run. We found that Mn in ZnO prefers substitutional Zn sites and Mn in Ge substitutional Ge...
Mr
Frank Wagner
(Technische Physik, Universität des Saarlandes, D-66041 Saarbrücken, Germany)
19/11/2008, 10:10
Understanding and control of diffusion profiles of intrinsic and extrinsic defects in semiconductors is of central importance for developing electronic and optoelectronic devices. In previous studies [1] it was shown that diffusion of Ag in CdTe can lead to uncommon diffusion profiles. The diffusion of Ag and Cu in CdTe crystals after implantation of 111Ag or 67Cu with 60 keV and annealing at...
Vitor Bras De Sequeira Amaral
(University of Aveiro)
19/11/2008, 10:30
Complex oxides, particularly manganites (R-D)MnO3 present a wealth of behaviours associated with coupled spin, lattice, charge and orbital degrees of freedom, that can be controlled by chemical doping. Perturbed Angular Correlation (PAC) studies in several systems were performed to locally probe these effects using the electric field gradient (EFG) and magnetic hyperfine field generated by the...
Thierry Stora
(CERN)
19/11/2008, 11:20
The activities related to Radioactive Ion Beam development at ISOLDE will be reviewed.
Mr
Liviu Constantin Penescu
(CERN)
19/11/2008, 11:50
Within the Marie Curie “HIGHINT” project a detailed study of the FEBIAD ion sources has been done at ISOLDE. As a result, two FEBIAD prototypes have been proposed and successfully tested. For the noble gases, the ionization efficiency was this way increased by about a factor 9, which allowed the identification of the new isotope 229Rn at ISOLDE. Due to this development, an increase of the...
Dr
Deyan Yordanov
(Max-Planck-Institut für Kernphysik)
19/11/2008, 14:15
The most recent highlights from collinear laser-spectroscopy at ISOLDE-CERN will be presented, including the charge-radius of the one-neutron halo 11Be as well as the spins and moments of 21Mg and of 71-75Cu. Specialized techniques have been used in each of these cases to further extend the reach of collinear laser spectroscopy to the extremes. Absolute frequency determinations with a...
Mr
Mane Ernesto
(University of Manchester)
19/11/2008, 14:45
The need for increasing the sensitivity of collinear laser spectroscopy has motivated the development of ion beam manipulation techniques. The ISOLDE ion beam cooler-buncher (ISCOOL) is well suited for this purpose. It has recently been installed at the focal plane of the high resolution separator magnets and is able to reduce the beam emittance by an order of magnitude, as well as release the...
Christopher Geppert
(Gesellschaft fuer Schwerionenforschung mbH (GSI), Darmstadt, Germany)
19/11/2008, 15:05
The aim of proposal IS449 is the determination of charge radii of the beryllium isotopic chain 7,9,10,11Be. For a precise extraction of charge radii, a precision of laser spectroscopy on the order of 1 MHz is needed. We have now used for the first time collinear laser spectroscopy to measure the isotope shift of radioactive isotopes to the accuracy required to extract charge radii by...
Mr
Vinzenz Bildstein
(Physik-Department E12, TU München)
19/11/2008, 15:25
Thirty years after the discovery of the ``island of inversion'' [1] the borders of the island are still not well determined and in particular the evolution of the single-particle structure is not well investigated.
Transfer reactions yield important spectroscopic information, i.e. spin and parity assignments as well as spectroscopic factors, complementary to the information obtained in...
Monika Stachura
(University of Copenhagen)
19/11/2008, 15:45
Perturbed angular correlation of γ-rays (PAC) spectroscopy is a techinque routinely used in solid state physics, however, it has also proved to be a method that allows for studies of biological problems, such as local structure at metal ion binding sites, dynamics of protein folding or protein–protein interactions [1].
In this work we illustrate that PAC spectroscopy is a suitable tool to...
Ms
Melanie Marie-Jeanne
(CERN)
19/11/2008, 16:05
At ISOLDE / CERN, an on-line test bench is dedicated to charge breeding experiments with a 14 GHz Phoenix ECRIS. The investigation of the 1+-->n+ scenario with exotic ion beams provides useful information for the design of the next generation of radioactive ion beam post-accelerators. The program of tests for the on-line performances was concluded this year. Possibilities of beam purification...
