METHOD OF PREDICTING LIFETIME OF FILAMENT OF ION SOURCE AND ION SOURCE DEVICE INCLUDING RESISTANCE VALUE OPERATION UNIT AND PREDICTION OPERATION UNIT

摘要

PURPOSE: A method and an ion source device are provided to accurately predict the lifetime of a filament even in cases where output of ion source is not constant, by measuring the resistance value of the filament which does not change even when the filament current changes. CONSTITUTION: A method comprises a step of continuously measuring the resistance value of a filament(10) during operation of an ion source(2) on the basis of the current flowing through the filament and voltages of both ends of the filament; and a step of predicting the lifetime of the filament until the filament is broken down on the basis of the change rate of the resistance value. An ion source device includes an ion source having a thermal electron emitting filament; a current measuring unit(26) for measuring the current flowing through a filament; a voltage measuring unit(28) for measuring voltages of both ends of the filament; a resistant value operation unit(32) for calculating resistance values of the filament on the basis of the current and voltage measured by the current measuring unit and the voltage measuring unit; and a prediction operation unit(34) for calculating the time where the filament reaches the limit of use or the residual time until the filament reaches the limit of use, by using the change rate of the resistance value calculated by the resistance value operation unit.