Excitation in collisions between potassium and rare gas atoms

Accurate measurements of the threshold behaviour for excitation of the states K(4 2 P 1 2/) and K(4 2 P 3 2/) have been performed for K+Ar, Kr, and Xe. Emission due to the decay of excited rare gas states has been studied for the same systems between 50 and 250 eV. The results show that the simultaneous excitation of both potassium and rare gas atom is not important in populating K(4 2 P). Excitation mechanisms are discussed on the basis of the molecular orbital model.