PhotoelectricK-Absorption Cross Section of Beryllium

Abstract

The continuous photoelectric absorption cross section of Be has been measured for photon energies extending from the $K$ edge energy, at 110 eV, to 180 eV. The measurements were carried out by the application of technical improvements which included a more precise electronic method for determining the surface density of absorbers and auxiliary equipment for transfering samples into the spectrograph without exposure to air. The theoretical results of the atomic photo-ionization cross section are also included for reference. The present data are compared with earlier measurements. The cross section ranges from a value of 1.01 Mb at 99.6 Å to a value of 0.63 Mb at 71.5 Å.