MASS SPECTROMETER WITH MULTIPLE CAPACITIVELY COUPLED MASS ANALYSIS STAGES

摘要

A mass spectroscopy apparatus having two quadrupole mass analyzer stages is disclosed. Both stages are configured to transmit ions of the same mass to charge ratio and they are operated in series to provide a tandem mass analyzer having greater resolution than either stage has separately. The poles of the two quadrupoles are positioned axially and close together to minimize ion loss between the two stages. The RF component of the potential across the two stages are kept in phase such that some poles of the first stage are always 180.degree. out of phase with some poles of the other stage. Capacitors are provided to couple the out of phase poles of the two stages to one another, thereby compensating for a stray capacitance which arises between the in phase poles of the two stages.