Collision between a high Rydberg ion and a neutral molecule

E. de Prunelé, J. Pascale

E. de Prunelé, J. Pascale

Byron George Zollars

Michio Matsuzawa

We have theoretically studied the conditions of the behavior of a high Rydberg electron as a spectator to an ion-molecule reaction in high Rydberg neutral collisions. Adoption of a circular high Rydberg atom in the initial channel of the high Rydberg neutral collisions ensures the behavior of the high Rydberg electron as the spectator to interaction between an ion core of the high Rydberg atom and an incoming neutral species; i.e., the ion-molecule reaction. This theoretical consideration leads to equivalence between the high Rydberg neutral collision and the ion-molecule reaction with high accuracy. This equivalence gives us a possibility of probing the ion-molecule reaction at low energies without space-charge effects encountered in ion-beam experiments.

F. B. Dunning, Sitti Buathong

Atoms in highly excited Rydberg states possess physical characteristics quite unlike those associated with atoms in the ground or low-lying excited states. In particular, they are physically very large and are only very weakly bound. In consequence, collisions can lead to a wide variety of reaction processes many of which are unique to Rydberg species and have very large collision cross sections. In collisions with neutral targets, Rydberg atoms behave not as an atom but rather as a pair of well-separated independent scatterers, namely the core ion and the excited Rydberg electron. In the present article we discuss many of the different reactions that can occur when Rydberg atoms collide with neutral targets, focusing principally on reactions that are dominated by (binary) Rydberg electron-target interactions and include collisions with molecules that attach free low-energy electrons and with polar targets. In certain situations, however, interactions involving the Rydberg core ion are important. This is illustrated using as an example the destruction of ultralong-range Rydberg molecules excited in a cold dense gas.

F. B. Dunning, R. F. Stebbings