Eur. Phys. J. A (2006) 28: 37-40
https://doi.org/10.1140/epja/i2006-10038-4

Nuclear Structure and Reactions

β-delayed proton decays and spin assignments for ¹⁴⁰Tb, ¹⁴¹Dy and ¹⁴³Dy

¹ Institute of Modern Physics, Chinese Academy of Sciences, 730000, Lanzhou, PRC
² Department of Technical Physics, Peking University, 100871, Beijing, PRC

^* e-mail: xsw@lzb.ac.cn

Received: 1 January 2006
Accepted: 4 May 2006
Published online: 29 May 2006

Abstract

The proton-rich isotopes ¹⁴⁰Tb and ¹⁴¹Dy were produced via the fusion evaporation reaction ⁴⁰Ca + ¹⁰⁶Cd. Their β-delayed proton decays were studied by p-γ coincidence in combination with a He-jet tape transport system, and half-lives, proton energy spectra, γ-transitions following the proton emission, as well as β-delayed proton branching ratios to the low-lying states in the grand-daughter nuclei were determined. Comparing the experimental data with statistical model calculations, the ground-state spins of ¹⁴⁰Tb and ¹⁴¹Dy were found to be consistent with 7 and 9/2, respectively. The configuration-constrained nuclear potential energy surfaces (NPES) of ¹⁴⁰Tb and ¹⁴¹Dy were calculated using the Woods-Saxon-Strutinsky method, which suggest the ground-state spins and parities of ¹⁴⁰Tb and ¹⁴¹Dy to be 7⁺ and 9/2^-, respectively. In addition, the configuration-constrained NPES of ¹⁴³Dy were calculated, which predict a 1/2⁺ ground state and a 11/2^- isomer with excitation energy of 198keV. These findings are consistent with our previous experimental data on ¹⁴³Dy reported in Eur. Phys. J. A 16, 347 (2003).