Ion deflector of an ionization gauge for extreme high vacuum

An ion deflector of an ionization pressure gauge for an extreme high vacuum use has been developed. On the basis of the calculated ion trajectories, the optimum deflection angles of the electrostatic cylindrical deflector have been determined versus the electrode gap: an excellent focusing of ion beam has been established at the optimum angles. This is important in order to use the channeltron and to remove the electron stimulated desorption (ESD) noise from the signals. We have realized a high efficiency of ion collection together with a large reduction of the two noises of soft x-ray photoemission current and ESD ions by using the ion deflector.