5 to 160 keV continuous-wave X-ray spectral energy distribution and energy flux density measurements

Techniques developed for measuring the X-ray spectral energy distribution (differential intensity) from a tungsten-target bremsstrahlung X-ray source are reported. Spectra with end-point energies ranging from 20 to 160 keV were recorded. A separate effort to calibrate the dosimetry for the Phillips Laboratory low-energy X-ray facility established a need to know the spectral energy distributions at some point within the facility (previous calibration efforts had relied on spectra obtained from computer simulations). It was discovered that the primary discrepancy between the simulated and measured spectra was in the L- and K-line data. The associated intensity (energy flux density) of the measured distributions was found to be up to 30% higher. Based on the measured distributions, predicted device responses were within 10% of the measured response as compared to about 30% accuracy obtained with simulated distributions.<>