X-Ray Absorption Coefficients of Thorium, Uranium, and Plutonium—Experimental Determination and Theoretical Interpretation

The x-ray absorption coefficients of thorium, uranium, and plutonium have been determined for the $K\alpha$ and $K\beta$ radiations of silver, molybdenum, copper, cobalt, iron, and chromium. Four absorption edges were found in the wavelength region covered. These were identified as the $L_{\mathrm{I}}$, $L_{\mathrm{II}}$, $L_{\mathrm{III}}$, $M_{\mathrm{I}}$, edges and a $M_{\mathrm{I}}$, $M_{\mathrm{II}}$ complex for plutonium. There is considerable disagreement between the experimental coefficients and the theoretical coefficients obtained from the Internationale Tabellen. Reasons for this discrepancy are discussed briefly. A correlation is obtained between the absorption of x-ray energy and the number of electrons in the $5f$ shell.