Advances Toward and Beyond the Proton Drip line with Recoil-Isomer Tagging
Abstract
This paper reviews the past, present and future status of recoil‐isomer tagging at the University of Jyväskylä. The main focus of this research has been to access isomeric states at and beyond the mass ≈140 proton drip line. Recoil‐isomer tagging was first used at the University of Jyväskylä in 1998 to establish the prompt rotational band built upon a Kπ = 8− isomeric state in 138Gd. Since that time a series of experiments have been performed which have studied isomeric states in the N = 77 isotones 63140Eu77, 65142Tb77 and 67144Ho77, and in the N = 74 K‐isomer chain, 64138Gd74 and 66140Dy74. These experiments have revealed valuable first information about deformations, single‐particle excitation energies and hindrance factors in nuclei at and beyond the proton drip line where little or no information previously existed.The results of the most‐recent experiments were discussed. These experiments established new isomeric states in 66143Dy77, 61136Pm75, and 64137Gd73 and a further two isomers which are currently unplaced. The paper concludes with a discussion of the future prospects for this research including the increased efficiency of the recoil‐isomer tagging technique with a new Multi‐Wire Proportional Counter (MWPC) detector which was designed and built at the University of Manchester. The first results from this new setup were shown.