Level Structure and Transition Probabilities in 165Tm and 167Tm

Svensson, L. - G., H. Solhed, N. - G. Jonsson, S. M. Darwish, and J. Lindskog, "Level Structure and Transition Probabilities in 165Tm and 167Tm", Physica Scripta , vol. 13, issue 4, pp. 193, 2007.


Transitions in 165Tm and 167Tm have been studied by means of the (p,nγ) and (p,2nγ) reactions. Singles gamma-ray spectra, gamma-gamma coincidences and conversion electron spectra have been recorded. The level schemes of both isotopes have partly been verified and new members of the 1/2-[541] band have been found in 167Tm. The halflives of three levels in the ground state bands have been measured using an electron-electron coincidence spectrometer: T1/2 = 322 ± 20 ps for the I = 7/2 level in165Tm, T1/2 = 343 ± 15 ps for the I = 7/2 level in 167Tm and T1/2 = 66 ± 7 ps for the I = 5/2 level in 167Tm. The electric and magnetic moments have been compared for the odd thulium isotopes. It was also shown that the quadrupole deformation 2 is constant and that the systematics of the single particle states in these isotopes only may be explained by variations of the hexadecapole deformation, 4 of the nuclear shape.