Eur. Phys. J. A (2020) 56: 143
https://doi.org/10.1140/epja/s10050-020-00153-5

Letter

Mass and half-life measurements of neutron-deficient iodine isotopes

¹ II Physikalisches Institut, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany
² GSI Helmholtzzentrum für Schwerionenforschung GmbH, 64291, Darmstadt, Germany
³ KVI-CART, University of Groningen, Groningen, The Netherlands
⁴ Tel Aviv University, 6997801, Tel Aviv, Israel
⁵ Soreq Nuclear Research Center, 81800, Yavne, Israel
⁶ IFIN-HH/ELI-NP, Măgurele, 077126, Bucharest, Romania
⁷ Saint Mary’s University, NS B3H 3C3, Halifax, Canada
⁸ University of Jyväskylä, 40014, Jyväskylä, Finland
⁹ TRIUMF, BC V6T 2A3, Vancouver, Canada

^* e-mail: s.ayet@gsi.de

Received: 15 December 2019
Accepted: 29 April 2020
Published online: 19 May 2020

Abstract

Neutron-deficient iodine isotopes, I and I, were produced at relativistic energies by in-flight fragmentation at the Fragment Separator (FRS) at GSI. The FRS Ion Catcher was used to thermalize the ions and to perform highly accurate mass measurements with a Multiple-Reflection Time-of-Flight Mass-Spectrometer (MR-TOF-MS). The masses of both isotopes were measured directly for the first time. The half-life of the I was measured by storing the ions in an RF quadrupole for different storage times and counting the remaining nuclei with the MR-TOF-MS. The measured half-life was used to assign the ground state to the measured I ions. Predictions on the possible -decay branch for I are presented based on the reduced uncertainties obtained for the -value. Systematic studies of the mass surface were performed with the newly obtained masses, showing better agreement with the expected trend in this mass region.