Desaktivierung angeregter He‐Atome (3 1 P 1 , 3 1 S 0 , 4 1 S 0 , 5 1 S 0 , 6 1 S 0 ) durch Rb‐Atome

Total collisional depopulation rates for He( n 1 S 0 ) (3 ≦ n ≦ 6), He(3 1 P 1 ) in thermal collisions with Rb have been measured using the transient‐decay method. The measured quenching cross‐sections increase from 4.3 · 10 −10 cm 2 to 24 · 10 −14 cm 2 with increasing n from 3 to 6. Comparison of experimental results with theoretical estimations shows that the main processes of quenching depend on n . He‐atoms in the n = 3, 4 states are mainly quenched by Penning ionisation and higher excited states by collisional l ‐mixing.