ZDependence and Angular Distribution of Bremsstrahlung from 17-Mev Electrons

Abstract

The relative bremsstrahlung cross section for the upper portion of the spectrum as a function of $Z$, for 17-Mev electrons from a 22-Mev betatron, has been measured. The radiation was detected by means of the ${\mathrm{Cu}}^{63}(\gamma ,n)$ induced activity, which has a 10.9-Mev threshold. The effect of atomic screening is small for the quantum energies to which this detector responds, but was taken into account. The results are in agreement with the Bethe-Heitler theory for electron-nuclear interactions within 1 percent. Electron-electron interactions give 0.75 times the intensity for electron-proton interactions, as measured with a copper detector.