Multi-Electrode Ion Trap

摘要

This invention relates generally to multi-reflection electrostatic systems, and more particularly to improvements in and relating to the Orbitrap electrostatic ion trap. A method of operating an electrostatic ion trapping device having an array of electrodes operable to mimic a single electrode is proposed, the method comprising determining three or more different voltages that, when applied to respective electrodes of the plurality of electrodes, generate an electrostatic trapping field that approximates the field that would be generated by applying a voltage to the single electrode, and applying the three or more so determined voltages to the respective electrodes. Further improvements lie in measuring a plurality of features from peaks with different intensities from one or more collected mass spectra to derive characteristics, and using the measured characteristics to improve the voltages to be applied to the plurality of electrodes.

主权项

1. A method of analyzing ions trapped in a trapping volume of a mass spectrometer, comprising:
providing a trapping volume defined between an inner electrode and an outer electrode surrounding the inner electrode, the inner electrode or the outer electrode comprise an array of plate electrodes extending in a spaced arrangement along a longitudinal axis of the trapping volume; applying voltages to the inner and outer electrodes, the voltages are applied to the array of ring electrodes thereby producing a trapping field to trap ions in a trapping volume such that the trapped ions adopt oscillatory motion along the longitudinal axis and remain constrained in the direction between the inner and outer electrodes; and detecting mass spectra from the trapped ions using image current detection, the period of oscillations along the longitudinal axis is subsequently independent on initial parameters of ions.