Patent ID: 11881388
Assignee: DH TECHNOLOGIES DEVELOPMENT PTE. LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method of performing mass analysis, the method comprising:
passing an ion beam comprising a plurality of ions continuously through a quadrupole assembly having a quadrupole rod set extending from an input end for receiving the ions to an output end through which ions exit the quadrupole rod set,
applying a first radial confinement signal to the quadrupole rod set so as to generate a first field for radially confining at least a first portion of the ions as they pass through the quadrupole rod set,
before or after applying the first radial confinement signal, applying a second radial confinement signal to the quadrupole rod set so as to generate a second field for radially confining at least a second portion of the ions as they pass through the quadrupole rod set, wherein the second radial confinement signal comprises at least one of a different RF voltage and DC voltage to the rods of the quadrupole rod set relative to an RF voltage and a DC voltage of the first radial confinement signal,
during the respective application of each of the first and second radial confinement signals, applying a voltage pulse across the quadrupole assembly so as to respectively excite radial oscillations of ions of the first and second portions at secular frequencies thereof, wherein fringing fields in proximity to said output end convert said radial oscillations into axial oscillations as said excited ions exit the quadrupole rod set,
detecting said axially oscillating ions exiting the quadrupole rod set for each of the first and second radial confinement signals to respectively generate a first time-varying signal and a second time-varying signal,
obtaining a Fourier transform of said first and second time-varying signals so as to generate a first frequency-domain signal and a second frequency-domain signal respectively,
utilizing said first and second frequency-domain signals so as to generate a first mass spectrum of the detected ions and a second mass spectrum of the detected ions, and
joining at least portions of the first and second mass spectra obtained under the first and second radial confinement signals.