J. Aysto | TrappedIons.org

Preparing isomerically pure beams of short-lived nuclei at JYFLTRAP

T. Eronen, V. -V. Elomaa, U. Hager, J. Hakala, A. Jokinen, A. Kankainen, S. Rahaman, J. Rissanen [1], C. Weber [1], J. Aysto

Abstract

A new procedure to prepare isomerically clean samples of ions with a mass resolving power of more than 100,000 has been developed at the JYFLTRAP tandem Penning trap system. The method utilises a dipolar rf-excitation of the ion motion with separated oscillatory fields in the precision trap. During a subsequent retransfer to the purification trap, the contaminants are rejected and as a consequence, the remaining bunch is isomerically cleaned. This newly-developed method is suitable for very high-resolution cleaning and is at least a factor of five faster than the methods used so far in Penning trap mass spectrometry.

Precise atomic masses of neutron-rich Br and Rb nuclei close to the r-process path

S. Rahaman, U. Hager, V. -V. Elomaa, T. Eronen, J. Hakala, A. Jokinen, A. Kankainen, P. Karvonen, I. D. Moore, H. Penttila, S. Rinta-Antila [1], J. Rissanen [1], A. Saastamoinen [1], T. Sonoda [1], J. Aysto

Abstract

The Penning trap mass spectrometer JYFLTRAP, coupled to the Ion-Guide Isotope Separator On-Line (IGISOL) facility at Jyvaskyla, was employed to measure the atomic masses of neutron rich 85 to 92Br and 94 to 97Rb isotopes with a typical accuracy less than 10 keV. Discrepancies with the older data are discussed. Comparison to different mass models is presented. Details of nuclear structure, shell and subshell closures are investigated by studying the two-neutron separation energy and the shell gap energy.