Vacuum-compatible air-cooled plasma device
US4659899A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1986 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | Feb 26, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J27/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A plasma generating device, and in particular a duoplasmatron ion gun, is disclosed that is air cooled, high vacuum compatible and hence very clean with a stable ion current output. The device is mounted to a standard type flange held at ground potential without the necessity of subsequent high voltage isolation. Cooling is achieved with cooling fins and a fan inside a housing in which the duoplasmatron is mounted. A mounting structure includes a vacuum tight ceramic ring brazed between the mounting flange and the gun body. The ceramic ring is located with respect to high permeability magnetic components and a magnetic coil to facilitate a magnetic field for focusing the plasma, allowing the coil to be referenced to ground potential while the gun is maintained at high voltage. A ceramic chamber containing ceramic pellets is located in the plasma-forming gas inlet duct to prevent high voltage electrical discharge in the gas duct. A piezoelectric valve operated by a pressure sensor maintains accurate gas flow and ion output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.