Crossed-beam determination of energy dependence of fine-structure transitions in K(4P)-He collisions

The energy dependence of the cross section for the process K(4P 1 2/)+He to K(4P 3 2/)+He has been measured in a crossed-beam experiment over the energy range 0.07-0.4 eV. Partial disagreement with previous results of Anderson et al., (1976), is observed. The variation of the cross section with energy is similar to that predicted by recent theoretical work. In particular the cross section has a nearly constant value for energies above 0.18 eV.