Measurement of the Total, Differential, and Exchange Cross Sections for the Scattering of Low-Energy Electrons by Potassium

Abstract

An atom beam recoil technique has been used to determine the total, $Q$, differential, $\sigma \left(\theta \right)$, and differential exchange, ${\sigma }_e\left(\theta \right)$, cross sections for the scattering of low-energy electrons by potassium. The method consists of observing the angular distribution of atoms scattered from a potassium atom beam which has been cross fired by an electron beam. Relative values of $\sigma \left(\theta \right)$ are then obtained by transforming to electron scattering angles. An inhomogeneous magnet and collimating channel are used as a velocity filter for the atom beam. Curves representing the variation of $\sigma \left(\theta \right)$ with $\theta$ between approximately 15° and 60° are presented for various electron energies between 0.6 and 9.0 ev.