Laser Resolution of Unpolarized-Electron Scattering Cross Sections into Spin-Conserved and Spin-Flip Components

The theory is presented for one-photon free-free absorption by electrons scattering from high-$Z$ atoms. The absorption cross section provides sufficient information to resolve the unpolarized-electron total cross section, ${\left|f\right(\theta \left)\right|}^2+{\left|g\right(\theta \left)\right|}^2$, into its individual components for spin-nonflip, ${\left|f\right(\theta \left)\right|}^2$, and spin-flip, ${\left|g\right(\theta \left)\right|}^2$, scattering. The observation of a spin-polarization effect for a spin-independent process (free-free absorption) is analogous to the Fano effect for bound-free absorption.