Experimental studies of the neutron-deficient gadolinium isotopes: ${}^{145}{Gd}^{m_{1}}$ and ${}^{145}{Gd}^{m_{2}}$

An isomer in

{}^{145}{Gd}

at 27.3 keV is reported with a half-life of 11.5 ± 0.3 nsec and an internal conversion coefficient

α_{L} = 16.9 \pm 1.4

. This state is described as substantially the

ν d_{\frac{3}{2}}

single-neutron state which is fed by the

{}^{145}{Gd}^{m_{2}}

ν h_{\frac{11}{2}}

isomer and which deexcites through the

ν s_{\frac{1}{2}}

ground state. The isomeric transition from

{}^{145}{Gd}^{m_{1}}

is found to be 99.2 ± 0.2%

M 1 + 0.8 \pm 0.2 %

E 2

, indicating a hindrance factor of 100 in the

M 1

and an enhancement factor of 40 in the

E 2

over the single-particle estimates. Recent information on the

N = 81

{\frac{11}{2}}^{-}

isomers is presented for

{}^{133}{Te}

through

{}^{147}{Dy}

showing the systematic changes in experimental energies and

M 4

matrix elements.

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Experimental studies of the neutron-deficient gadolinium isotopes:Gdm1145andGdm2145