Mass spectrometer and electron impact ion source thereof
US5561292A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1995 |
| Grant date | Oct 1, 1996 |
| Priority date | — |
| Expiry date | May 15, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An enclosed ion source for generating substantially monoenergetic ions from a gaseous sample comprises a chamber into which the gaseous sample is introduced and which is substantially enclosed by a source block having two electron entrance apertures formed in it and by a source plate having one ion extraction aperture formed in it. Two filaments are disposed outside the chamber and adjacent the electron entrance apertures. The electron impact ion source is characterized by the provision of an electrically conductive shield which is disposed within the chamber and which defines an equipotential region. The electrons, generated from a heated filament, pass into the chamber through one of the electron entrance apertures. The shield allows the passage of molecules of the gaseous sample and the electrons into the equipotential region, so that electron impact ionization of at least some of the sample occurs in the equipotential region. The electron impact source may be incorporated into a conventional mass spectrometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.