Ab initio modeling of Cs - Mo interfaces in negative ion sources

The paramount relevance of Cs as a catalyst in negative ion sources used in nuclear fusion studies is not balanced by an appr opriate knowledge of the microphysical properties of Cs interface with high performance metals in this field, particularly Mo. In this study the interaction of Cs with Mo under conditions of interest for negative ion sources is studied using different meth ods. A Cs - Mo potential is formulated for Cs interaction with Mo in gas phase and Mo[001]. Mo - Mo and Cs - Cs potentials are based on new fits of the data present in the literature. The use of these potentials is illustrated by classical MD calculations for Cs partial layers on Mo[001]. In perspective this study can contribute with sound physical data to the ongoing effort to improve the performance of Cs catalyzed negative ion sources.