Patent ID: 8513592
Filing Date: 2013-08-20
Classification: H01J

Abstract:
1. An ion trap mass spectrometer comprising: an ion trap to confine ions in a space surrounded by three or more electrodes; a positive voltage DC power supply; a negative voltage DC power supply; a switch on a positive electrode side that turns on and off the positive voltage output from said positive voltage DC power supply; a switch on a negative electrode side that turns on and off the negative voltage output from said negative voltage DC power supply; a square-wave voltage generation means for outputting a square-wave voltage to at least one of said electrodes by using the positive and negative voltages supplied through each of said switches on both positive and negative electrode sides when such switches are on, for trapping ions; a positive electrode side waveform area calculation means for calculating the area of the square-wave voltage on the positive electrode side that is applied to at least one of said electrodes; a negative electrode side waveform area calculation means for calculating the area of the square-wave voltage on the negative electrode side that is applied to at least one of said electrodes; and a feedback adjusting means for adjusting the timing of change of at least one of control signals that turn on and off said switches on the positive and negative electrode sides in order to level the areas calculated by said positive electrode side waveform area calculation means and negative electrode side waveform area calculation means.