Optical activity for neutrons

Abstract

When a neutron passes through an optically active medium, the transverse component of its polarization should precess around the direction of propagation of while the longitudinal component should increase (or decrease) monotonically. For a representative medium, in a typical case, the rotatory power for neutron polarization is expected to be of order ${10}^{\ensuremath{-}5}$ ${\mathrm{cm}}^{\ensuremath{-}1}$. The rate of acquisition of longitudinal polarization is also expected to be of similar magnitude, and the $\ensuremath{\gamma}$ rays associated with thermal neutron capture should have circular polarization of order ${10}^{\ensuremath{-}7}$.