Excitation transfer in the 2p levels of Ne due to collisions with ground-state He atoms

Excitation transfer between the four adjacent 2p 2 to 2p 5 levels of Ne I due to collisions with ground-state He atoms has been investigated. Three of these levels were, in separate experiments, populated by pumping Ne 1s 5 metastables present in a flowing afterglow using a pulsed tunable dye laser; and the subsequent fluorescent decay of the four adjacent levels observed. Of the twelve possible cross sections for excitation transfer between these levels, ten have been determined and upper bounds established for the remaining two.