Absorption coefficients for Al, Cu and Ag in the X-ray region from 13 to 24 A

Abstract

It may be seen from Table I that there is only one determination in the X-ray region above 10 A, a fact which is probably due to the experimental difficulties attached to the measurements in this region. The difficulties of vacuum technique and of using a grating at grazing incidence involved in isolating the homogeneous X-radiations in the long wave-length region are well known. Furthermore, because of the highly absorbable character of these radiations the metal absorbing laminae must be extremely thin, and homogeneous laminae, so essential for absorption investigations, are not readily obtainable in these thicknesses. Bandopadhyaya and Maitra (1936) found that the mass absorption coefficients for Al in the region 8-25 A do not vary with wave-length according to the generally accepted relation μ / p = Cλ n , (1) where C and n are constants. They observed a decrease in the value of n as the wave-length increased.