Investigation ofA=155 andA=151 nuclides: Identification of the ${}^{155}{Tm}$ $s_{1 / 2}$ isomer and of the ${}^{155}{Yb}$ β-decay branch

The decay properties of

{}^{155}{Lu}

{}^{155}{Yb}

{}^{155}{Tm}

, and of the α-decay daughters

{}^{151}{Er}

and

{}^{151}{Ho}

were investigated following the on-line mass separation of A=155 nuclides produced in

{}^{64}{Zn}

irradiations of

{}^{95}{Mo}

. In the study, the half-life of the low-spin isomer in

{}^{155}{Lu}

was measured to be 140±20 ms, the β-decay branch of

{}^{155}{Yb}

was identified by observing daughter γ rays and Tm K x rays, and the existence in

{}^{155}{Tm}

of an

s_{1 / 2}

isomer (

T_{1 / 2}

=44±4 s), in addition to the

h_{11 / 2}

ground state (

T_{1 / 2}

=21.6±0.2 s) was established. Schemes for the β decays of

{}^{155}{Yb}

{}^{155}{Tm}

, and

{}^{151}{Er}

are proposed. New information on

{}^{151}{Er}

decay establishes the

s_{1 / 2}

isomer in

{}^{151}{Ho}

to be 41.1±0.2 keV above the

h_{11 / 2}

ground state. Also, branchings of 90±5, 28±7, and

80_{- 20}^{+ 15}

% were determined for the α decays of

{}^{155}{Yb}

{}^{151}{Ho}

, and

{}^{151}{Ho}^{m}

, respectively.

This publication has 21 references indexed in Scilit:

Investigation ofA=155 andA=151 nuclides: Identification of theTm155s1/2isomer and of theYb155β-decay branch