Precision Measurement of X-Ray Spectra with Application to the L X-Ray Spectra of Uranium, Neptunium, Plutonium, and Americium

Citation

Merrill, John Jay (1960) Precision Measurement of X-Ray Spectra with Application to the L X-Ray Spectra of Uranium, Neptunium, Plutonium, and Americium. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/81EA-4141. https://resolver.caltech.edu/CaltechETD:etd-06272006-131143

Abstract

Techniques for the precision measurement of X-ray lines using the two-crystal spectrometer are discussed, and then applied to measurement of the L X-ray spectra of the trans-uranic elements uranium, neptunium, plutonium and americium. In all, 52 emission lines and 4 L(III) absorption edges were measured, all of them with higher precision than has heretofore been obtained and many of them for the first time. Using these data, the binding energies of the electrons for these atoms were computed. The L(II)-L(III) level splitting was computed and compared with theory and it was found that current theory is not sufficient to account quantitatively for the observed data. Certain features of the emission line widths are discussed and given qualitative explanations in terms of the Coster-Kronig transition L(II)-L(III)M(V) and hyperfine structure. The observed hyperfine structure is due to the large magnetic moment of Np237 which leads to increased widths of certain of the Np lines. It is believed that this is the first experimental observation of hyperfine structure in X-ray spectra.

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