Method and apparatus for analyzing trace components using a gas curtain
US4137750A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 1977 |
| Grant date | Feb 6, 1979 |
| Priority date | — |
| Expiry date | Apr 25, 1997 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/0422
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for analyzing trace components contained in a sample gas. The sample gas is directed into a reaction chamber and ionized. The resultant trace ions are drifted by an electric field, out of the sample gas, through an inert gas curtain and then through an orifice into a vacuum chamber where they are focused and analyzed. The curtain gas flow may be greater than the flow through the orifice, in which case the gas curtain acts as an ion window which is transparent to ions but blocks sample gas flow into the vacuum chamber. Alternatively, the curtain gas flow may be controlled to admit a desired flow of sample gas through the curtain into the vacuum chamber, in which case the gas curtain acts as a window for ions and as an infinitely variable orifice for the sample gas. Preferably the curtain gas is cryopumpable and is cryopumped by cooling the interior surface of the vaccum chamber.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.