Penning and associative ionisation of highly excited rubidium atoms

Highly excited and resonant states are created in a rubidium vapour in order to study the collisional ionisation with the ground state and between these different excited species. A mass analysis allows one to separate the atomic and molecular channels. Penning ionisation with a resonant state is shown to have a great efficiency (rate coefficient greater than 10 -8 cm 3 s -1 ) for all the highly excited levels under study (6d, 8s, 7d). The associative ionisation rate coefficient between these excited atoms and a ground-state atom lies in the expected range 10 -10 to 5*10 -10 cm 3 s -1 and seems to be independent of l j and values.