TheKAbsorption Discontinuities of the Elements Zirconium to Iodine

A study of the $K$ absorption limits in the elements Zr, Cb, Mo, Ru, Rh, Pd, Ag, Cd, Sn, Sb, Te, and I has been made with a double-crystal spectrometer. All of the elements studied except cadmium show faint fine structure on the high frequency side of the discontinuity, the structure appearing as narrow bands of slightly decreased absorption lying within a range of from 21 to 120 volts of the main discontinuity. The width of the main absorption step in volts has been measured and found to increase with atomic number. Defining the wave-length of the absorption discontinuity as that corresponding to the point of inflection of the main absorption curve values of the wavelength have been obtained to an estimated accuracy of ±0.02 x.u.