Continuum emission during ion-atom collisions at high projectile energies

A general formalism to treat radiative emission of a colliding three-particle system is developed in the semiclassical approximation. The matrix element of the matter-radiation interaction is separated into three terms representing the center of mass, the intersystem bremsstrahlung, and the electron bremsstrahlung. At each step we impose the off-shell orthogonality property of the mechanical wave functions. Instead of internuclear bremsstrahlung, used so far, a more general concept of intersystem bremsstrahlung is introduced. The electron bremsstrahlung is calculated using eikonal distorted wave functions, and good agreement is found with experiment. Radiative electron excitation and deexcitation have also been calculated. The former is found to be very small, while the spectrum associated with the latter produces the continuous emission around the characteristic line, induced by the passing projectile.