Internal Conversion Electrons from Electric Excitation ofTa181,Au197, andPt195

Conversion electrons from the electric excitation of ${\mathrm{Ta}}^{181}$, ${\mathrm{Au}}^{197}$, and ${\mathrm{Pt}}^{195}$ have been studied with a magnetic spectrometer. From $\frac{K}{L}$ ratios, multipolarities have been assigned to the following transitions: Ta 137 kev, $0.93 M1+0.07\mathrm{} E2\mathrm{}$; Au 279 kev, $0.75 M1+0.25\mathrm{} E2\mathrm{}$; Pt 210 kev, $M1\mathrm{}$. Direct excitation of the 77-kev level in Au has been observed with a reduced transition probability for excitation of (0.18±0.06)×${10}^{-48\mathrm{}}$ ${\mathrm{cm}}^4$ $e^2$. Measured excitation functions indicate levels in Pt at 29 and 126 kev, instead of at 97 and 126 kev, as assigned from radioactive decay studies. Apparent single-particle transitions in Au and Pt have $E2\mathrm{}$ transition probabilities an order of magnitude larger than single-particle estimates.