On the Polarization of High Energy Bremsstrahlung and of High Energy Pairs

The polarization of bremsstrahlung due to electrons with initial energies much larger than $137{Z}^{\ensuremath{-}\frac{1}{3}}m{c}^{2}$ is calculated under relativistic, small angles approximations. The cross section for photons polarized normally to the plane containing the initial direction of the electron and the direction of the photon is found to be larger than for photons polarized in that plane. A similar calculation shows that the plane containing one of a pair produced by a polarized photon together with the direction of that photon tends to lie parallel to the plane of polarization rather than normal to it, except for one special case. The effect of the deviation due to multiple scattering of electrons in the target upon the angular dependence of the polarization is considered.