Ionization of Long-Lived Highly Excited Atoms by Collision with Molecules

For the ionization of long-lived highly excited atom A** by collision with molecule B A**+B→A++B+e, a mechanism is proposed in which an electron in the long-lived highly excited atom is ionized as a result of its energy gain from the molecule by the rotational de-excitation. The cross sections at thermal velocities are calculated to be of the order of 10−13 cm2 for polar molecules according to the proposed mechanism. This result is in reasonable agreement with experimental data.