JPS5478198A - Electrode - Google Patents

Abstract

PURPOSE: To control the passing of charged particles by preventing the passing of neutral particles, by providing a specific means in the passing hole of charged particles in the electrode for ion source of mass spectrograph.

CONSTITUTION: Conductors 52 are laminated by way of an electric insulator 50, along the axial direction of the inner wall of ion emission hole 12 in ionization chamber 10 which is held at a proper potential with respect to ion accelerating electrode 20 which is earthed by a direct current power source 26. And stepwise potential difference is applied between the respective conductors 52 due to direct current power source 54 and resistor 56. As a result, a potential gradient as shown by dotted line is created, and, at the same time, as in the conventional constitution, an extending electric field due to the electrode 20 is generated in the vicinity of elecrtron beam, 28, so that the ions are converged and accelerated regardless of the size of thickness l of the hole 12. That is, the conductance of hole 12 can be controlled if necessary by properly increasing the thickness l, and the ion passing efficiency may be increased by the potential gradient through the multilayer electrode.

COPYRIGHT: (C)1979,JPO&Japio