Multipole reaction chamber for chemical ionisation - with inlet and outlet coaxial to multipole electrodes

摘要

Reaction chamber for the chemical ionisation of atoms and molecules by ion/molecule reactions contains an electrical multiple with >=4 radially symmetrical insulated pole rods to which high-frequency a.c. voltages are applied in turn. The inlets and/or outlets are near the axis of symmetry. The total internal pressure is such that the mean free path of the ions and molecules is smaller than the diametral distance between the poles. Arrangement provides a simple means of producing ions of the reactant gas for the chemical ionisation of the molecules of the substance to be analysed. The ions are concentrated near the outlet and blown out by the gas stream. A larger outlet does not increase the high vacuum load.