A Crossed‐Beam Apparatus for Investigation of Ion‐Molecule Reactions

A crossed‐beam apparatus for the study of ion‐molecule reactions is described. The device can provide information on the velocity and angular spectra of reaction products as well as on the angular displacement between reactant and product ions. It can thus yield data sufficient to provide a detailed characterization of the dynamics of the system studied. Furthermore, the mass selected ion beam is variable in energy from 100 eV down to the critical low energy region of about 1 eV or less. Although the apparatus thus seems to have broader capabilities than previously described beam devices, it is quite small and comparatively inexpensive.