Comment on radiation tail and radiation correction for electron scattering experiments

The number of electrons must be corrected for additional processes before this number can be interpreted in terms of single contribution. This procedure is currently denoted by ''radiation correction''. The electrons, which lose energy by these additional processes, yield continuous background, ''radiation tail''. Both problems are normally dealt with independently, and the formulae for the radiation correction do not fit correctly into those for the radiation tail. In addition, the formulae contain some inconsistency in themselves. The correct correction factors Ksup(fol) was calculated by integrating numerically the folded radiation tail. Since the correction factors from the folding procedure and from the product of three single contributions agree quite well for larger ΔE, the approximation for the radiation tail was calculated by taking the derivative of the product of three correction factors. The normalization of this tail function gsup(prod) was the same as that of the folded tail. The agreement between this approximation and the exact procedure is of the order of 1% for ΔE=2 MeV. So this approximation may be used for saving computer time. (Tai, I.)