Absorption of X-Rays

Abstract

AT the suggestion of Prof. Richardson, we have for some time been engaged in an investigation of the connection between X-ray absorption coefficients and critical frequencies. In this work we have met with considerable experimental difficulties, which so far have not been completely overcome. It appears, however, that one of the questions we had set ourselves can be answered, partially at any rate, from some data recently published by Richtmeyer (Phys. Rev., July, 1921, p. 13), who has given the absorption curves of molybdenum and silver for homogeneous X-rays on both sides of their respective critical (K) absorption frequencies, and for lead on the longer wave-length side. Data on lead have been previously given by Hull and Rice (Phys. Rev., vol. 8, p. 326, 1916), who have also determined one point on the shorter wave-length side. The values of Richtmeyer for lead are proportionately higher than those of Hull and Rice, apparently indicating that the latter have inaccurately determined the thickness of their thin absorbing screen.