| 摘要 |
PURPOSE:To reduce a change in ion detecting limitation to securely detect ions in an entire measurement range by switching over magnetic field intensity according to a mass range of ions to be detected. CONSTITUTION:An exciting current source Sb converts a digital data signal corresponding to magnetic field intensity from a controller C into electric current. An ion accelerating voltage source Sa converts a digital data signal corresponding to ion accelerating voltage from the controller C into voltage. Ion accelerating voltage is to be taken as a constant value per stage, wherein voltage may be varied in a sawtooth state within a micro width with a specific voltage as the center during a time per stage of the ion accelerating voltage and mass scanning may be performed within the micro mass range. Thus a small shift of the ion accelerating voltage and the magnetic field with respect to a peak to be detected while the ion accelerating voltage and magnetic field intensity are to changed in steps can be covered thereby securely detecting ions of a mass to be detected. |
