Angle-Energy Distribution of Radiation from High-Energy Electron Accelerators

An energy-analyzing detector of the pair-spectrometer type has been used to observe the angular distribution of bremsstrahlung produced by 17-Mev monokinetic electrons in molybdenum betatron targets. Distributions were measured for gamma-ray energies of 7, 11, and 15 Mev, for each of three targets whose thicknesses were approximately 2, 5, and 21 mils. Reproducible variations of spectrum with angle were found, the variations becoming more pronounced with increasing target thickness. The experimental distributions are compared here with the theoretical distributions of Schiff and Lawson, the former being significantly narrower. Axial relative spectra are also presented.