Limiting migration of target material
US9564283B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2012 |
| Grant date | Feb 7, 2017 |
| Priority date | — |
| Expiry date | Mar 29, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2235/16
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In an electron irradiation system, a gas-tight housing encloses a cathode region and an irradiation region, which communicate through at least an aperture. In the cathode region, there is arranged a high-voltage cathode for emitting an electron beam. In the irradiation region, there is an irradiation site arranged to accommodate a stationary or moving object to be irradiated. The migration of cathode-degrading debris is limited by means of an electric field designed to prevent positively charged particles from entering the cathode region via the aperture. The invention can be embodied with an axial electric field, which realizes an energy threshold, or a transversal field which deflects charged particles away from trajectories leading into the cathode region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.