Ion chambers for fluorescence and laboratory EXAFS detection

Abstract It is possible to design gas ionization chambers with a noise equivalence of 10 3 photons/s for 10 keV X-radiation. With such a low noise level, ion detectors can be used for laboratory EXAFS facilities and fluorescence detectors at national synchrotron facilities where the detected signal is above 10 3 photons/s. In such use the ion chambers are limited by statistical noise and produce as good a signal to noise as counting detectors. The advantages of ion chambers are simplicity, high linearity at high counting rates and large detecting area.