Broadening of the x-ray emission line due to the instrumental function of the double-crystal spectrometer

The influence of the instrumental function on the Cu Kα₁ emission line was investigated for the case of a double-crystal spectrometer. The magnitude of broadening for both Si(220) and Si(440) was calculated for a Lorentzian emission line with the width of 1--5 eV; the broadening for Si(220) is 0.12--0.18 eV while that for Si(440) is only 0.015--0.043 eV. The former is too large to be neglected, so the correction for the instrumental function is important. The spectrum affected by the instrumental function seems to keep the shape of Lorentzian though its width is larger. The fact indicates that the Lorentzian fitting analysis is effective if the appropriate correction for width is done.