Transitions between the components of the fine structure in He and He-Like ions colliding with protons

The cross sections for the transitions between the components of the fine structure of triplet levels with n = 2 and 3 in He and He-like ions colliding with protons have been considered. The feature of the problem is the presence of a virtual level coupled with the components of the multiplet by dipole-allowed transitions. As a result, the cross section at intermediate collision velocities has a peak, which is sometimes much higher than the cross section for the transition induced by collisions with electrons. The cross sections for He and C⁴⁺ and Fe²⁴⁺ ions have been calculated by the tight-binding method.