Theory of continuum emission during ion-atom collisions

Abstract
Two new sources of continuum photon emission accompanying heavy-ion collisions have been identified recently, namely radiative electron capture and molecular orbital emission. Separate theoretical treatments have indicated that such emissions occur when the collision is fast or slow respectively compared to the orbital velocities of initially bound electrons. A unified treatment is presented, applicable to any nonrelativistic collision velocity. The emission amplitude appears as that for radiative transition between two scattering states of the ion-atom collision system. The separate limits of high- and low-velocity collisions are considered in detail and expressions are derived for the frequency, impact-parameter and angular dependences of the photon emission.