Absorption and Counting-Efficiency Data for X-Ray Detectors

Abstract
Mass absorption coefficient data published by Allen, Bragg, and Victoreen for the wavelength region 0.1 to 50 A are plotted for several common x-ray tube and counter windows (Al, Be, and mica) and gases (Xe, Kr, A, and Ne) used in x-ray detectors. A graph of the calculated percentage transmission of the windows is presented. The calculated quantum-counting efficiencies for the range 0.1 to 15 A are shown for an end-window argon-filled Geiger counter, side-window Xe, Kr, A, and Ne proportional counters and an NaI·Tl scintillation counter. Some of the factors to be considered in the choice of detectors for x-ray diffractometry and x-ray spectroscopy are discussed particularly with respect to the spectral sensitivity.