Radioactivity of neutron deficient isotopes in the regionN>82>Z

Rapid Communication: First Observation of y-Ray Emission Assigned to the Decay of 164W

“…Eastham et al [3] W were first produced by Toth et al [4] in the reaction ,56 Dy ( 16 0, xn). Additional data on 16°-,66 w reported in [5,6] were confirmed by these authors. For 164 W α-branches of 2.6% [5] or 5% [6] and for ,65 W < 1.5% [5] are reported; the other decay mode is electron capture or ß + -decay.…”

“…Additional data on 16°-,66 w reported in [5,6] were confirmed by these authors. For 164 W α-branches of 2.6% [5] or 5% [6] and for ,65 W < 1.5% [5] are reported; the other decay mode is electron capture or ß + -decay. Therefore, y-lines of these nuclides can be expected but are so far unknown.…”

Evolution of collective structures in the heavy transitional nuclei above the N = 82 closed shell

“…Figure 2(b) and 2(c) show the variation of the excitation energies of the low-lying yrast states in the Re and Ta isotopes, respectively. The lightest even-N Re and Ta isotopes have ground states that are near-spherical and based on the low-Ω s 1/2 or d 3/2 proton states with a low-lying isomer formed by exciting the odd proton into the high-Ω h 11/2 state [21][22][23][24][25][26]. Gamma rays associated with the characteristic radioactive decays of the h 11/2 isomer in 157 Ta [27] (N = 84), 159 Ta [4] and 161 Re [28] (N = 86) have revealed non-collective excited states formed by coupling the odd proton to the few valence neutrons in f 7/2 , h 9/2 and i 13/2 states.…”

Collective excitations in the transitional nucleiRe163andRe165

“…2, was deduced from the analysis of 2.4 × 10 5 γ γ coincidences correlated with the α decays of 163 Re. The recoil-decay time correlation was limited to 214 ms to reduce false correlations with the dominant reaction channel 163 W, which has a longer α-decay half-life, t 1/2 = 2800(170) ms [27]. − state was measured to be 115.1(40) keV in previous work by Davids et al [26].…”

“…Previous decay-spectroscopy experiments have identified α-decay branches from both the 1/2 + ground state and a low-lying 11/2 − isomer in 165 Re [27][28][29]. The α-decay properties of the 1/2 + ground state [E α = 5556(6) keV, t 1/2 = 1600(600) ms, b α = 14(8) nuclei have similar α-decay properties, the α decays of their daughters can easily be distinguished.…”