Backscattering and transmission through a high Z interface as a measure of electron beam energy

The ratio of electron beam transmission (Tr) and backscattering (Bs) is used as a measure of beam energy. With a proper thickness of high Z medium placed at the surface of a low Z homogeneous medium, it is observed that the function log(Tr/Bs) is a linear function of electron energy. This method is applied to electrons produced with scattering foil and pulse-swept (scanned) beams for the nominal energies ranging from 6 to 20 MeV. This technique provides a unique alternative method which is easy, simple, and accurate within +/- 3% for estimation of electron beam energy.