Adjusting field conditions in linear ion processing apparatus for different modes of operation

摘要

Methods for applying an RF field in a two-dimensional electrode structure include applying RF voltages to one or more main electrodes and compensation electrodes. The voltages on the one or more compensation electrodes may be adjusted to be proportional to the voltages on the main electrodes. The adjustment(s) may be done to optimize the RF field for different modes of operation such as ion ejection and ion dissociation. For dissociation and other procedures involving ion excitation, the voltages applied to the one or more compensation electrodes may be different from the voltages applied to the one or more main electrodes. Electrode structures may include main trapping electrodes, one or more compensation electrodes, one or more ion exit apertures, and a device or circuitry for applying the various desired voltages.