The K X-Ray Absorption of Calcium in Calcite, Gypsum, and Fluorite

Abstract

Fine structure of the K x-ray absorption edge of calcium.—The K x-ray absorption edge of calcium has been photographed with the object of studying the fine structure of the edge. The absorption occurred in the reflecting crystal itself, thus rendering unnecessary any absorbing material other than the crystal. Three crystals were used—calcite, gypsum, and fluorite. The fine structure of the edge shows as many as four subdivisions. The explanation is probably, as suggested by Kossel, that the electron ejected from the K orbit by the absorption stops in some of the unoccupied orbits, and in case of a calcium ion which we undoubtedly have in these crystals, the energy difference of these different virtual orbits is sufficient to show as a fine structure of the edge.