Method of removing unwanted charged particles from the measuring cell of an ICR spectrometer

摘要

For eliminating undesirable charged low-mass particles from the measuring cell of an ion cyclotron resonance spectrometer the electrodes normally required for exciting the cyclotron movement are supplied with an rf voltage having a frequency twice as high as the resonance frequency of the trapping oscillation of the charged particles between the trapping electrodes provided perpendicularly to the homogenous magnetic field of the spectrometer. In this manner, the low-mass charged particles are excited to perform trapping oscillations in the direction of the homogenous magnetic field which cause the charged particles to overcome the trapping potentials and, thus, to be eliminated.