Mass spectrometer with reduced static electric field
US4931640A · kind A · utility
Inventors
Key dates
| Filing date | May 19, 1989 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | May 19, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/38
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An ion cyclotron resonance cell (20) in which samples are analyzed has plates (21, 22) serving as excitation electrodes, top and bottom plates (25, 26) serving as detector electrodes and end trapping plates (23, 24). The cell (20) is maintained in a magnetic field of flux density B oriented longitudinally between the end trapping plates (23, 24). An ion generating source (30) causes ionization of the sample molecules within the cell (20). An electrostatic trapping potential is applied to the end trapping plates (23, 24) to prevent ions from escaping in the direction of the magnetic field B. Grounded screens (40, 41) are positioned within the cell (20) just inside the end trapping plates (23, 24) to reduce an electrostatic electric field in the cell (20) resulting from the application of a potential to the end trapping plates (23, 24).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.