Mass Assignments of 23-secPd107mand 4.8-minPd109m; Search for <3-secPd105m

Abstract

The formation of the 23-sec and 4.8-min Pd isomers by neutron activation of ${\mathrm{Pd}}^{106}$ and ${\mathrm{Pd}}^{108}$ samples leads to the mass assignments 23-sec ${\mathrm{Pd}}^{107m}$ and 4.8-min ${\mathrm{Pd}}^{109m}$. Both isomers decay by isomeric transition with considerable conversion only and are not formed in the $\ensuremath{\beta}$ decay of the corresponding Rh isotopes. The spin assignments ($\frac{11}{2}\ensuremath{-}$) could be confirmed. No isomeric state of ${\mathrm{Pd}}^{105}$ was found, and it is concluded that its half-life will be shorter than 3 sec.