A space-time buffer includes a plurality of discrete trapping regions and a controller. The plurality of discrete trapping regions is configured to trap ions as individual trapping regions or as combinations of trapping regions. The controller is configured to combine at least a portion of the plurality of trapping regions into a larger trap region; fill the larger trap region with a plurality of ions; split the larger trap region into individual trapping regions each containing a portion of the plurality of ions; and eject ions from the trapping regions.

A space-time buffer includes a plurality of discrete trapping regions and a controller. The plurality of discrete trapping regions is configured to trap ions as individual trapping regions or as combinations of trapping regions. The controller is configured to combine at least a portion of the plurality of trapping regions into a larger trap region; fill the larger trap region with a plurality of ions; split the larger trap region into individual trapping regions each containing a portion of the plurality of ions; and eject ions from the trapping regions.

Control of an amplitude of a signal applied to a component of a mass spectrometer is described. In one aspect, a mass spectrometer includes a component and a resonant circuit to generate a radio frequency (RF) signal applied to the component. An amplitude control circuit can be inductively coupled with inductors of the resonant circuit to selectively discharge energy from the resonant circuit and, therefore, adjust the amplitude of the signal in particular situations.

The invention generally relates to systems and methods for collision induced dissociation of ions in an ion trap. In certain aspects, the invention provides a system that includes a mass spectrometer having an ion trap, and a central processing unit (CPU). The CPU includes storage coupled to the CPU for storing instructions that when executed by the CPU cause the system to generate one or more signals, and apply the one or more signals to the ion trap in a manner that all ions within the ion trap are fragmented at a same Mathieu q value.

A data acquisition method for a mass spectrometer includes providing at least one ion source for generating ions; not fragmenting or less fragmenting the ions when a collision cell is in a first working mode; recording a mass spectrum of the ions generated in the first working mode; selecting more than one ion from the ions, the more than one ion being distributed in a plurality of discontinuous mass-to-charge ratio channels; partially fragmenting the selected ions when the collision cell is in a second working mode; recording a mass spectrum of the ions generated in the second working mode; and, repetitively executing the above steps for several times. The ions distributed in the discontinuous mass-to-charge ratio channels is always selected during the subsequent repeated execution, until the ion intensity of the selected ions is less than a set value.

A data acquisition method in a mass spectrometer includes a. providing an ion source to generate precursor ions; b. feeding the precursor ions into a first mass analyzer that selects one mass window such that the precursor ions located outside the mass window pass through the first mass analyzer and the precursor ions located within the mass window cannot pass through the first mass analyzer; c. feeding the precursor ions passing through the first mass analyzer into a collision cell for collisional dissociation, to generate product ions; d. feeding the product ions into a second mass analyzer for mass analysis and recording a spectrum; and e. repeating Steps b-d. Each time when Step b is repeatedly performed, the selected mass window does not overlap with all the mass windows previously selected. After all the mass windows in a mass range are selected, the repetition is stopped.

In one aspect, a mass analyzer is disclosed, which comprises a quadrupole having an input end for receiving ions and an output end through which ions can exit the quadrupole, said quadrupole having a plurality of rods to at least some of which an RF voltage can be applied for generating a quadrupolar field for causing radial confinement of the ions as they propagate through the quadrupole and further generating fringing fields in proximity of said output end. The mass analyzer further includes at least a voltage source for applying a voltage pulse to at least one of said rods so as to excite radial oscillations of at least a portion of the ions passing through the quadrupole at secular frequencies thereof, where the radially-excited ions interact with the fringing fields as they exit the quadrupole such that their radial oscillations are converted into axial oscillations.

A method of fragmenting ions comprises: injecting first ions of a first charge into an ion trap that includes an elongate multipole electrode assembly defining an elongate ion channel; radially confining the first ions within the ion channel by applying an RF pseudopotential to the electrode assembly and axially confining said ions to a first volume within the ion channel by applying a first potential well to the ion channel; injecting second ions of a second charge opposite to the first charge into the ion trap; axially confining the second ions to a second volume within the ion channel by applying a second potential well to the ion channel, the first potential well being within the second potential well; cooling the first and second ions in the ion trap; and allowing the ions to interact such that the first ions and/or second ions are fragmented to produce product ions.

An ion resonance excitation operation method and device by applying a quadrupolar electric field combined with a dipolar electric field. The method includes applying a main RF to any pair of plates of the ion trap mass analyzer, and applying a quadrupolar excitation signal to any pair of plates, and applying a reverse phase dipolar excitation signal to any pair of plates. Also provided is an ion resonance excitation operation method and device by using a quadrupolar electric field combined with a dipolar electric field, which includes applying a positive main RF to a pair of electrode rods of the quadrupole, and applying a negative main RF to the other pair of electrode rods; applying a quadrupolar excitation signal to any pair of electrode rods, applying a reverse phase dipolar excitation signal to any pair of electrode rods.

Systems and methods are disclosed for ion injection into an electrostatic trap. As non-limiting examples, various aspects of this disclosure provide a quadrupole comprising first, second, and third quadrupole segments. The second quadrupole segment may be arranged between the first and third quadrupole segments and the first quadrupole segment and the third quadrupole segment may each comprise four poles with auxiliary electrodes arranged between each pair of the four poles. The second quadrupole segment may comprise four poles and the first and third quadrupoles each may comprise four individual auxiliary electrodes, two pairs of auxiliary electrodes, two electrodes, or one pair of auxiliary electrodes. The auxiliary electrodes of the first quadrupole segment and the entrance lens may be biased at a same direct current (DC) voltage. The auxiliary electrodes of the third quadrupole segment and the exit lens may be biased at a same DC voltage.