Particle detection by electron multiplication
US6982428B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 16, 2004 |
| Grant date | Jan 3, 2006 |
| Priority date | — |
| Expiry date | Apr 30, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J49/025
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Electron focussing apparatus includes a cathode plate defining an impact surface on which particles impact, which surface has a finite probability of generating at least one electron for each impacting particle having predetermined characteristics. The apparatus also has an electron receiving element, and respective means for generating electrostatic and magnetic fields in a space extending from the impact surface to the electron receiving element. The means for generating the electrostatic and magnetic fields are configured whereby the E/B2 ratio adjacent the electron receiving element is smaller than adjacent the impact surface, whereby to decrease the radius of curvature of the electron trajectories adjacent the electron receiving element relative to adjacent the impact surface and to thereby focus the electron trajectories in at least one dimension. In another aspect the electron receiving element is positioned and the means for generating the electrostatic and magnetic fields are configured to cause the electrons to deflect on average through greater than 180° before impacting the electron receiving element, whereby to focus, in at least one dimension, multiple electrons gener…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.