Scattering analysis of NO clusters in a new molecular beam machine

Abstract

Nitric oxide clusters which are generated in a supersonic expansion of NO in Ne carrier gas are size selected by a scattering process with He atoms. The experiments are carried out in a new universal crossed molecular beam machine with a movable detector part which allows an easy change of different detection schemes and time-of-flight analysis of the scattered particles. By measurement of angular dependent mass spectra and TOF distributions the fragmentation due to electron impact ionization is measured at 70 eV. For (NO) n clusters up to n = 5 no other product channels than those of the dimer ion (NO) 2 +, the monomer ion NO + and N + are observed. The preferred fragment ion, however, is NO + for n = 2, 3, and 4.