Non-Elastic Processes in Atom Rydberg-Atom Collisions: Review of State of Art and Problems

In our previous research, it has been demonstrated that inelastic processes in atom Rydberg-atom collisions, such as chemi-ionization and (n-n') mixing, should be considered together. Here we will review the present state-of-the-art and the actual problems. In this context, we will consider the influence of the (n-n')-mixing during a symmetric atom Rydberg-atom collision processes on the intensity of chemi-ionization process. It will be taken into account H(1s) + H (au)(n) collisional systems, where the principal quantum number is n >> 1. It will be demonstrated that the inclusion of (n-n') mixing in the calculation, influences significantly on the values of chemi-ionization rate coefficients, particularly in the lower part of the block of the Rydberg states. Different possible channels of the (n-n')-mixing influence on chemi-ionization rate coefficients will be demonstrated. The possibility of interpretation of the (n-n')-mixing influence will be considered on the basis of two existing methods for describing the inelastic processes in symmetrical atom Rydberg-atom collisions.