Coulomb Excitation of States in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">Th</mml:mi></mml:mrow><mml:mrow><mml:mn>232</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">U</mml:mi></mml:mrow><mml:mrow><mml:mn>238</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>

The yield of gamma rays resulting from Coulomb excitation of states in ${\mathrm{Th}}^{232}$ and ${\mathrm{U}}^{238}$ with protons of 4- to 6-Mev energy have been measured. Gamma rays of 790-, 740-, and 613-kev energy from ${\mathrm{Th}}^{232}$ and of 1.02-Mev energy from ${\mathrm{U}}^{238}$ are observed. For ${\mathrm{Th}}^{232}$, the variation in gamma-ray yields with proton energy, the results from gamma-ray angular distributions, and the linear polarization measurements are consistent with the direct excitation of a 2+ state at 790-kev which decays by means of $E2$ radiation to the $I=0+ \mathrm{and} 2+$ members of the ground-state rotational band. In view of the recent results from internal conversion electron measurements at Rice University, the 613-kev gamma ray is interpreted to be a transition from a $2+\ensuremath{\beta}$-vibrational state at 773 kev to the 4+ state at 163 kev. An interpretation of the observed gamma-ray yields is carried out taking a $\ensuremath{\gamma}$-vibrational state at 790 kev and a $\ensuremath{\beta}$-vibrational state at 773 kev. The $B{(E2)}_{d}$ of the 2+ state at 50 kev in ${\mathrm{Th}}^{232}$ is about 150 times the single-particle estimate. The $B{(E2)}_{d}$ of the vibrational states in ${\mathrm{Th}}^{232}$ and ${\mathrm{U}}^{238}$ are between 2 and 4 times the single-particle estimate. Combining Bernstein's relative internal conversion electron yields with our gamma-ray data, a value of (8\ifmmode\pm\else\textpm\fi{}2)\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}2}$ for the strength parameter $\ensuremath{\rho}$ is obtained for the $E0$ transition between the 2+ state at 773 kev and the 2+ state at 50 kev in ${\mathrm{Th}}^{232}$.

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