Compact penning-discharge plasma source
US4800281A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 24, 1986 |
| Grant date | Jan 24, 1989 |
| Priority date | — |
| Expiry date | Oct 24, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J27/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A compact, quick-igniting, and high-efficiency Penning-discharge type plasma source which comprises a cathode means for thermionically emitting electrons; an electron emission means disposed inside the cathode; anode means defining a discharge space, for accelerating electrons emitted by said cathode means and said emission means into the discharge space; means for supplying gas to be ionized to the discharge space; and heating means for initially heating the emission means. In a preferred embodiment, the anode means is a planar anode. Initial heating of the emission means by the heater causes electrons to be emitted therefrom. These electrons are accelerated by the planar anode to ionize the gas in the discharge space. An axial magnetic field with axial maximum near the exit aperture in the planar anode optimizes ionization and causes most of the plasma production to occur near the exit aperture, thereby enhancing efficiency of the source. Most of the ions produced exit the source before recombination. The other ions impact the cathode, cause heating and induce thermionic emission, thereby rendering further heating of the emission means unnecessary. A method of igniting a Penning-…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.