Time-separated oscillatory fields for high-precision mass measurements on short-lived Al and Ca nuclides

¹  GSI - Planckstraße 1, 64291 Darmstadt, Germany
²  Institut für Physik, Johannes Gutenberg-Universität - 55099 Mainz, Germany
³  CSNSM-IN2P3-CNRS - 91405 Orsay-Campus, France
⁴  Centre d'Etudes Nucléaires de Bordeaux-Gradignan - 33175 Gradignan Cedex, France
⁵  Max-Planck-Institut für Kernphysik - 69117 Heidelberg, Germany
⁶  Institut für Physik, Ernst-Moritz-Arndt-Universität - 17487 Greifswald, Germany
⁷  Department of Physics, University of Jyväskylä - P.O. Box 35 (YFL), 40014 Jyväskylä, Finland
⁸  CERN, Physics Department - 1211 Geneva 23, Switzerland
⁹  Physikalisches Institut, Ruprecht-Karls-Universität - 69120 Heidelberg, Germany
¹⁰  NSCL, Michigan State University - East Lansing, MI 48824-1321, USA

Corresponding author: george@uni-mainz.de

Received: 10 January 2008
Accepted: 11 April 2008

Abstract

High-precision Penning trap mass measurements on the stable nuclide ²⁷Al as well as on the short-lived radionuclides ²⁶Al and Ca have been performed by use of radiofrequency excitation with time-separated oscillatory fields, i.e. Ramsey's method, recently extended to Penning trap mass measurements of radioactive isotopes. A comparison with the conventional method of a single continuous excitation demonstrates the advantage of up to ten times shorter measurements. The new mass values of Al are compared to literature values and clarify conflicting data in this mass region. In addition, the resulting mass values of the superallowed β-emitter ³⁸Ca as well as of the ground state of the β-emitter ²⁶Al^m confirm previous measurements.