The?-decay of100Y: Discovery of a very low lying 0+ state in100Zr

Abstract

The /?-decay of lOOy has been investigated at the gas filled recoil separator JOSEF by means of 7-ray and conversion electron spectroscopy. Two B-decay modes, of half lives 0.94 + 0.03 s and 0.55 _+ 0.15 s, have been observed. Using XV-, Xce-, V7-and 7ce-coincidences the level scheme of ~~176 has been constructed. An excited 0~-state at 331.3 keV has been discovered in this nucleus. The/~-decay from the 0.55 s decay mode in 10oy shows a strong preference for the ground state compared to the 0~-state in ~~176 The structure of l~176 and the nature of the 0~ level is discussed in the light of the present results.

β-decay half-lives andβ-delayed neutron emission probabilities of nuclei in the regionA≲110, relevant for the r process

“…In some particular cases, half-lives from β-decay isomers were found in the literature. In particular, Khan et al [59] reported two different half-lives for 100 Y 61 , presumably from low-and high-spin β-decaying isomers. The T 1/2 measured in the present experiment for this nucleus is compared in Fig.…”

Theβ-decays of99Y and99Zr and the level schemes of99Zr and99Nb

“…The intensity decrease fits to a B-half life of 1.00_+0.13s [25]. Hence a/s-decaying isomeric state must exist in 99y.…”

Magnetic moments of the 2 1 + states in102, 104Mo

“…Experimental [1][2][3][4] as well as theoretical [5][6][7] studies of the region of neutron-rich nuclei around A = 100 have established the fact that a few isotopic chains (i.e. St, Zr, Mo) exhibit a rapid transition from vibrational to rotational structure when the number of neutrons is increased beyond N= 60.…”