Measurement and calculation of absolute intensities of x-ray spectra

Calculations and measurement of the continuum spectra of Cr and W x-ray tubes operated at 45 kV are compared. The calculation is based on the Boltzmann transport equation and the bremsstrahlung cross sections of Kirkpatrick and Wiedmann. The measurements use a crystal spectrometer whose efficiency is well known. The calculations and experimental data are in agreement within ±5% on a relative basis and within ±30% on an absolute basis.