Collisions of high-Rydberg atoms in circular states with He

Abstract
The collisional properties of high-Rydberg atoms in circular states with mod m mod =l approximately=n have been theoretically investigated using the free electron model. It has been found that the highly anisotropic electron density distribution of the circular state manifests itself as the propensity rule in which state changing occurs overwhelmingly between circular states in collisions with He.