Probing Sizes and Shapes of Nobelium Isotopes by Laser Spectroscopy

Until recently, ground-state nuclear moments of the heaviest nuclei could only be inferred from nuclear spectroscopy, where model assumptions are required. Laser spectroscopy in combination with modern atomic structure calculations is now able to probe these moments directly, in a comprehensive and nuclear-model-independent way. Here we report on unique access to the differential mean-square charge radii of 252, 253, 254No, and therefore to changes in nuclear size and shape. State-of-the-art nuclear density functional calculations describe well the changes in nuclear charge radii in the region of the heavy actinides, indicating an appreciable central depression in the deformed proton density distribution in 252, 254No isotopes. Finally, the hyperfine splitting of 253No was evaluated, enabling a complementary measure of its (quadrupole) deformation, as well as an insight into the neutron single-particle wave function via the nuclear spin and magnetic moment

Application of a thin double-sided microstrip detector for the registration of beta-delayed charge particles: The He-6 beta decay into the two-body continuum of Li-6

We present a method for the detection of charged particles. emitted following beta decay, that allows to reduce the background due to beta radiation and thus to facilitate separation of the delayed-particle events, The isotopes of interest are implanted into a highly segmented double-sided silicon strip detector, resulting in excellent precision on the overall normalisation. The characteristics of the detector and the particle signatures are discussed, This method can be applied to a variety of systems close to the proton and neutron driplines. it region which the recent availability of post-accelerated radioactive beams has opened up for study. To demonstrate this, we measured the branching ratio of He-6 beta decay into the alpha + d two-body continuum of Li-6. We obtained it Value of(1.7 +/- 04) x 10(-6) for energies x + d above 525 keV. (c) 2005 Elsevier B.V. All rights reserved.status: publishe

Application of a thin double-sided microstrip detector for the registration of beta-delayed charge particles: The He-6 beta decay into the two-body continuum of Li-6

We present a method for the detection of charged particles. emitted following beta decay, that allows to reduce the background due to beta radiation and thus to facilitate separation of the delayed-particle events, The isotopes of interest are implanted into a highly segmented double-sided silicon strip detector, resulting in excellent precision on the overall normalisation. The characteristics of the detector and the particle signatures are discussed, This method can be applied to a variety of systems close to the proton and neutron driplines. it region which the recent availability of post-accelerated radioactive beams has opened up for study. To demonstrate this, we measured the branching ratio of He-6 beta decay into the alpha + d two-body continuum of Li-6. We obtained it Value of(1.7 +/- 04) x 10(-6) for energies x + d above 525 keV. (c) 2005 Elsevier B.V. All rights reserved

Large Shape Staggering in Neutron-Deficient Bi Isotopes

The changes in the mean-square charge radius (relative to Bi-209), magnetic dipole, and electric quadrupole moments of Bi-187,Bi-188,Bi-189,Bi-191 were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in Bi-187,188,189(g), manifested by a sharp radius increase for the ground state of Bi-188 relative to the neighboring Bi-187,189(g). A large isomer shift was also observed for Bi-188(m). Both effects happen at the same neutron number, N = 10(5), where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.Peer reviewe

In gas laser ionization and spectroscopy experiments at the Superconducting Separator Spectrometer (S3): Conceptual studies and preliminary design

The results of preparatory experiments and the preliminary designs of a new in-gas laser ionization and spectroscopy setup, to be coupled to the Super Separator Spectrometer S3 of SPIRAL2-GANIL, are reported. Special attention is given to the development and tests to carry out a full implementation of the in-gas jet laser spectroscopy technique. Application of this novel technique to radioactive species will allow high-sensitivity and enhanced-resolution laser spectroscopy studies of ground- and excited-state properties of exotic nuclei.publisher: Elsevier articletitle: In gas laser ionization and spectroscopy experiments at the Superconducting Separator Spectrometer (S3): Conceptual studies and preliminary design journaltitle: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms articlelink: http://dx.doi.org/10.1016/j.nimb.2013.07.028 content_type: article copyright: Copyright © 2013 Elsevier B.V. All rights reserved.status: publishe

Probing Sizes and Shapes of Nobelium Isotopes by Laser Spectroscopy

Until recently, ground-state nuclear moments of the heaviest nuclei could only be inferred from nuclear spectroscopy, where model assumptions are required. Laser spectroscopy in combination with modern atomic structure calculations is now able to probe these moments directly, in a comprehensive and nuclear-model-independent way. Here we report on unique access to the differential mean-square charge radii of ^{252,253,254}No, and therefore to changes in nuclear size and shape. State-of-the-art nuclear density functional calculations describe well the changes in nuclear charge radii in the region of the heavy actinides, indicating an appreciable central depression in the deformed proton density distribution in ^{252,254}No isotopes. Finally, the hyperfine splitting of ^{253}No was evaluated, enabling a complementary measure of its (quadrupole) deformation, as well as an insight into the neutron single-particle wave function via the nuclear spin and magnetic moment.numpages: 6status: Published onlin