Patent ID: 8742330
Filing Date: 2014-06-03
Classification: H01J

Abstract:
1. An ion trap device comprising an ion source which supplies pulsed ions and an ion trap which traps the ions supplied from said ion source by means of an electric field formed in a space surrounded by a plurality of electrodes, characterized in that it comprises a) a voltage application means which applies a square wave high frequency voltage to at least one of the plurality of electrodes making up said ion trap in order to form a high frequency electric field for capturing ions in said ion trap; and b) a control means which controls said voltage application means so as to inject the ions supplied in pulses from said ion source into said ion trap in a state where said square wave high frequency voltage is not applied to said at least one electrode, and start the application of said square wave high frequency voltage from a specified phase after a predetermined period of time has elapsed in order to trap the injected ions, wherein the specified phase is at an intermediate point of a single duty cycle of the square wave.