The Decay ofRh104m(4.3 Min) andRh104(44 Sec)

Abstract

The radiations of neutron-activated rhodium are studied with 180\ifmmode^\circ\else\textdegree\fi{} constant field conversion electron spectrometers and a gamma-ray scintillation spectrometer. Internal conversion electrons are observed to be associated with the 4.3-minute activity. These are interpreted as arising from two isomeric transitions of 51.1\ifmmode\pm\else\textpm\fi{}0.2 and 77.2\ifmmode\pm\else\textpm\fi{}0.2 kev in rhodium. By coincidence studies these two transitions are shown to be in cascade. The character of the radiations, as determined from the $\frac{K}{L}$ ratios and lifetime considerations, appears to be $M1$ and $E3$, respectively. Additional gamma-rays of energy 550\ifmmode\pm\else\textpm\fi{}10 kev and \ensuremath{\sim}1.2 Mev (weak) are observed with the scintillation spectrometer. The 550-kev transition is associated with both the 44-second and the 4.3-minute periods and is assumed to follow the beta-decay and hence be in ${\mathrm{Pd}}^{104}$.