US 12,488,978 B2
Digital linear ion trap and method for operating the same
Kei Kodera, Kyoto (JP)
Assigned to SHIMADZU CORPORATION, Kyoto (JP)
Filed by SHIMADZU CORPORATION, Kyoto (JP)
Filed on Apr. 13, 2022, as Appl. No. 17/719,454.
Prior Publication US 2023/0335388 A1, Oct. 19, 2023
Int. Cl. H01J 49/42 (2006.01); H01J 49/16 (2006.01)
CPC H01J 49/422 (2013.01) [H01J 49/161 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A linear ion trap, comprising:
two first rod electrodes arranged so as to face each other across a central axis, each of the first rod electrodes having an opening;
two second rod electrodes arranged so as to face each other across the central axis, in a direction different from a direction in which the two first rod electrodes face each other;
a pair of end electrodes respectively arranged outside two end faces of the two first rod electrodes and the two second rod electrodes;
a radio-frequency voltage supplier configured to apply a radio-frequency voltage for capturing ions, the radio-frequency voltage supplier being electrically connected only to each of the two second rod electrodes among the two first rod electrodes and the two second rod electrodes;
an excitation voltage supplier configured to apply a voltage for resonance excitation, the excitation voltage supplier being electrically connected only to each of the two first rod electrodes among the two first rod electrodes and the two second rod electrodes; and
a controller configured to control the radio-frequency voltage supplier and the excitation voltage supplier,
wherein the controller is configured so that:
when an ion having a predetermined mass-to-charge ratio is to be captured within a space surrounded by the two first rod electrodes, the two second rod electrodes and the pair of end electrodes, the controller controls the radio-frequency voltage supplier so as to apply, only to each of the two second rod electrodes among the two first rod electrodes and the two second rod electrodes, a radio-frequency voltage having a frequency corresponding to the mass-to-charge ratio of the ion; and
when an ion captured within the space is to be ejected, the controller controls the excitation voltage supplier so as to apply the voltage for resonance excitation only to each of the two first rod electrodes among the two first rod electrodes and the two second rod electrodes while continuing applying the radio-frequency voltage only to each of the two second rod electrodes by the radio-frequency voltage supplier,
wherein one of the openings of the two first rod electrodes is an ion introduction port, and
wherein one or both of the openings of the two first rod electrodes is an ion ejection port.