The Fine Structure of the X-Ray Absorption Limits of Bromine and Chlorine

The ratio of the absorption coefficient of the bromine atom in ${\mathrm{Br}}_2$ to that in HBr for monochromatic x-rays is calculated as a function of the x-ray wave-length in the region of the $K$-absorption edge according to the theory as given by Petersen. A predicted minimum at about 5.9 volts on the high frequency side of the absorption edge agrees satisfactorily with the experimental findings in position but not in intensity. A predicted broad maximum at about 15 volts from the absorption edge is not found experimentally. The structure for chlorine is recalculated from the Hartree self-consistent field for the chlorine atom and is compared with previous photographic measurements.