Electron impact study of carbon disulphide micro-clusters

The production of carbon disulphide micro-clusters (CS2)(n) n less than or equal to 11, by adiabatic gas expansion of mixture of CS2 vapour and Ar is studied by using an electron impact ion source and a double focusing sector field mass spectrometer. The appearance potentials for clusters n less tha n or equal to 9 decreased as n increased but was not a simple function of 1 /n. The appearance pressures of observed clusters showed a slowly increasin g dependence on cluster size. Results of measurements of appearance potenti als and appearance pressures of selected clusters are described for a range of operating conditions. (C) 1999 Elsevier Science Ltd. All rights reserve d.