Quantitative characterization of an x-ray source in an x-ray photoelectron spectroscopy system

The x-ray spectrum from a dual anode x-ray source in an x-ray photoelectron spectroscopy system was calculated by the NIST Desk Top Spectrum Analyzer used for synthesizing spectra in energy dispersive x-ray analyzers commonly found in scanning electron microscopes. The energy flux was obtained by integrating over the x-ray energy spectrum. The energy flux from the source was measured by a silicon photodiode. Very good quantitative agreement was found between the flux obtained from the calculated spectra and the flux measured by the photodiode, indicating that the calculated spectra are, in fact, physically valid for this source. The calculated spectra were used to obtain the energy deposition as a function of depth below the irradiated surface of polytetrafluoro- ethylene, a material used in spacecraft and exposed to the space radiation environment.