Dielectric capillary high pass ion filter
US6486469B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1999 |
| Grant date | Nov 26, 2002 |
| Priority date | — |
| Expiry date | Oct 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
For delivery of ions from a higher pressure ion source to a mass analyzer operating at high vacuum, high pass ion filtration is effected within a dielectric capillary interface between the higher pressure ionization chamber and the lower pressure environment of a mass analyzer, by application of electrical potentials to end electrodes and to at least one electrode associated with the dielectric capillary between the ends, to create an end-to-end electric field generally opposing gas flow-assisted movement of ions from the upstream end to the downstream end, and to create a steeper voltage gradient along an upstream portion than along a downstream portion of the capillary. The voltage gradient along the steeper upstream portion of the capillary is sufficiently steep to cause ions having drift velocities below a lower limit to stall within the capillary. The respective potentials may be adjusted to increase the steepness of the upstream voltage gradient to increase the drift velocity lower limit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.