Coherence between the excitation of states with different energies

Abstract

In recent experiments we have shown both in electron impact and in photoionisation studies the possibility to determine coherences between the excitation of states of different energies. In this paper the consequences of applying coincident techniques to these experiments are discussed. In a coincidence experiment one has to choose, however, for lower energy resoltuions in order to reach sufficient count rates. We present an experiment which shows that these lower resolutions do not totally osbcure the formely observed interference effects, thus proving the feasibility of a future coincidence experiment