Nuclear Data Evaluation for 217Th

S.S. Nafeea,b, A.M. Al-Ramadyc and S.A. Shaheena aKing Abdulaziz University, Faculty of Science, Physics Department, 20589 Jeddah, Saudi Arabia bAlexandria University, Faculty of Science, Physics Department, 21121 Alexandria, Egypt cKing Abdulaziz University, Deanship for Post Graduate Studies, 20589 Jeddah, Saudi Arabia

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Thorium-217 was produced by the reaction 170Er (50Ti, xn) 220-xTh. The nuclei were studied by Evaporation Residues gamma-alpha-gamma coincidence measurements (ER-γ-α-γ). The evaluated decay data for the 217Th nuclide resulted from the above interaction is presented in this report. Three delayed γ-transitions (309, 673 and 1269 keV) have been measured from the ER-γ(-γ)-α correlations and γ-γ coincidences. They were assigned to 217Th, based on the level systematics of the N=127 isotones. The evaluated half-lives T1/2 for these levels were assigned to be 64-22+64, 69-17+32 and 66-15+27 μs, respectively. In addition, an isomeric state (2252+x) keV is presented in the 217Th decay scheme between the 2252 (21/2+) and 2362 (25/2+) keV. Q (α) has been updated based on the recent published work of the Atomic Mass Evaluation AME2012 as well. Moreover, the total conversion: electrons as well as the K-Shell to L-Shell, L-Shell to M-Shell and L-Shell to N-Shell conversion electron ratios have been calculated using BrIcc code v2.3.

DOI: 10.12693/APhysPolA.129.669 PACS numbers: 21.10.-k, 23.20.-g, 23.35.+g, 29.30.-h