Mass spectrometer
US6794640B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 2002 |
| Grant date | Sep 21, 2004 |
| Priority date | — |
| Expiry date | Nov 22, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/42
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A mass spectrometer is disclosed comprising a mass selective ion trap such as a 3D quadrupole field ion trap upstream of a pusher electrode of an orthogonal acceleration Time of Flight mass analyzer. According to a first embodiment bunches of ions are released from the ion trap and the pusher electrode is energised after a delay time which is progressively varied. According to a second embodiment ions are released from the ion trap in reverse order of mass to charge ratio with the ions having the largest mass to charge ratio being released first. By appropriate release of the ions from the ion trap it is possible to ensure that substantially all of the ions arrive at the pusher electrode at substantially the same time. According to both embodiments it is possible to achieve a duty cycle approaching 100% across a large range of mass to charge ratios.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.