Y. Y. Zhong

Ground-state and decay properties of neutron-rich 106Nb

A. J. Mitchell [1], R. Orford [2,3], G. J. Lane [1], C. J. Lister [4], P. Copp [4], J. A. Clark [3], G. Savard [3,5], J. M. Allmond [6], A. D. Ayangeakaa [7,8], S. Bottoni [3], M. P. Carpenter [3], P. Chowdhury [4], D. A. Gorelov [3,9], R. V. F. Janssens [7,8], F. G. Kondev [3], U. Patel [1], D. Seweryniak [3], M. L. Smith [1], Y. Y. Zhong [1], S. Zhu [3]

Abstract

The ground-state properties of neutron-rich 106Nb and its beta decay into 106Mo have been studied using the CARIBU radioactive-ion-beam facility at Argonne National Laboratory. Niobium-106 ions were extracted from a 252Cf fission source and mass separated before being delivered as low-energy beams to the Canadian Penning Trap, as well as the X-Array and SATURN beta-decay-spectroscopy station. The measured 106Nb ground-state mass excess of -66202.0(13) keV is consistent with a recent measurement but has three times better precision; this work also rules out the existence of a second long-lived, beta-decaying state in 106Nb above 5 keV in excitation energy. The decay half-life of 106Nb was measured to be 1.097(21) s, which is 8% longer than the adopted value. The level scheme of the decay progeny, 106Mo, has been expanded up to approximately 4 MeV. The distribution of decay strength and considerable population of excited states in 106Mo of J >= 3 emphasises the need to revise the adopted Jpi = 1- ground-state spin-parity assignment of 106Nb; it is more likely to be J => 3.