New crossed-beam apparatus for the study of ion–molecule collision processes

Abstract

A new crossed‐beam apparatus for the study of ion–molecule collision processes is described. Among the novel features of this apparatus are a high pressure ’’chemical ionization’’ ion source, an apertureless exponential ion deceleration lens, a product ion mass/energy analyzer that can be scanned in angle through nearly a full octant of a sphere, and a supersonic nozzle molecular beam source. The high pressure source can be used to produce vibrationally relaxed ground state reactant ions, and the deceleration lens produces focused ion beams with energies as low as 0.1 eV at intensities equal to the space‐charge limit.