Speaker
Dr
Deyan Yordanov
(Max-Planck-Institut für Kernphysik)
Description
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 frequency comb have allowed isotope-shifts measurements of very light radioactive isotopes for the first time with sufficient precision to extract charge radii. Beta-asymmetry detection was used for magnesium and cooling and bunching with ISCOOL was applied for the first time in order to study copper and gallium isotopes. This emphasizes the diverse capabilities of modern laser spectroscopy.
The charge radii of 7,9,10,11Be have been determined [1] by high-precision collinear-anticollinear spectroscopy combined with absolute frequency determination by a frequency comb. The achieved accuracy of the isotope-shifts in the transition 2s 1/2->2p 1/2 of Be+ is better than 1 MHz. Accurate atomic-physics calculations are used to eliminate the mass-dependent isotope shift and extract the nuclear volume effect. The charge radii decrease from 7Be to 10Be and increase again for the halo nucleus 11Be. From a simple frozen-core two-body model a root mean square distance of about 7 fm between the halo neutron and the center of mass in 11Be is obtained.
The spin and magnetic moment of 21Mg have been measured with highly sensitive beta-asymmetry detection [2]. These are important parameters for studying the nuclear mirror symmetry in the pair 21F-21Mg (T=3/2). A discussion in terms of isoscalar and isovector parts of the magnetic moment will be presented. The isoscalar moment surprisingly lies outside the empirical boundaries given by the Schmidt moments. Shell-model calculations taking in to account isospin nonconservation can reproduce this effect.
The very first results from online laser spectroscopy with the ISOLDE radio-frequency cooler and buncher (ISCOOL) will be presented, namely the hyperfine-structure and isotope-shift measurements of neutron-rich gallium and copper isotopes. The case of copper, in particular, will be discussed in terms of the shell model and the monopole migration of the proton 1f5/2 orbital [3].
[1] W. Nortershauser et al., Phys. Rev. Lett., submitted September 2008, http://arxiv.org/abs/0809.2607.
[2] J. Kramer et al., publication in progress.
[3] K. T. Flanagan et al., publication in progress.
Author
Dr
Deyan Yordanov
(Max-Planck-Institut für Kernphysik)
Co-authors
Mr
A Krieger
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz)
Dr
B Cheal
(University of Manchester)
Dr
C Geppert
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz, and GSI)
Dr
D Forest
(School of Physics and Astronomy, University of Birmingham)
Mr
D Tiedemann
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz)
Mr
E Mane
(University of Manchester)
Prof.
G Neyens
(Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven)
Prof.
H Stroke
(New York University)
Prof.
J Billowes
(University of Manchester)
Mr
J Kramer
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz)
Prof.
K Blaum
(Max-Planck-Institut für Kernphysik)
Dr
K Flanagan
(Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven, and IPN Orsay)
Dr
M Avgouleva
(Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven)
Dr
M Bissell
(Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven)
Ms
M De Rydt
(Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven)
Dr
M Kowalska
(CERN, Physics Department)
Ms
M Zakova
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz)
Prof.
P Lievens
(Laboratorium voor Vaste-Stoffysica en Magnetisme, Katholieke Universiteit Leuven)
Mr
P Vingerhoets
(Instituut voor Kern- en Stralingsfysica, Katholieke Universiteit Leuven)
Prof.
R Neugart
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz)
Dr
R Sanchez
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz)
Prof.
W Nortershauser
(Institut fur Kernchemie, Johannes Gutenberg-Universitat Mainz, and GSI)
