Mass spectrometer for positive and negative ions
US4810882A · kind A · utility
29Cited by
4References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 4, 1988 |
| Grant date | Mar 7, 1989 |
| Priority date | — |
| Expiry date | Mar 4, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a mass spectrometer capable of detecting both positive and negative ions. Positive ions emerging from the mass analyzer strike a conversion electrode to release secondary electrons which pass through an annular electrode to strike a phosphor, releasing photons. Negative ions strike the surface of the annular electrode to release secondary electrons which also strike the phosphor, releasing photons. The photons are detected with a conventional photomultiplier. The electrodes are biased and disposed so that both positive ions and negative ions may be detected without changing the potentials applied to them.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.