A practical method for the energy measurement of therapeutic electron beams based on Multiple Scattering Theory

Periodic energy measurements of therapeutic electron beams are critical for assuring patient safety. In this paper, a low cost and reliable method based on Multiple Scattering Theory and the use of a simple ionization chamber has been proposed. The energy is determined by measuring mass scattering power derived from the spatial distribution of a pencil beam in air, obtained from a broad electron beam. The pencil beam distribution is calculated by subtracting the dose distributions obtained from the lead sheets with and without an aperture in the center. The experimental results of this method have been shown to be in agreement with the conventional Rp and R/sub 50/ water phantom measurement techniques.