Vacuum measuring gauge
US7352187B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 27, 2006 |
| Grant date | Apr 1, 2008 |
| Priority date | — |
| Expiry date | Apr 26, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J41/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electron-emitting cathode consists of an electrically conducting emitter layer attached to a side wall which consists of stainless steel and a gate which is fixed at a mall distance inside a concave emitter surface of the emitter layer. The cathode surrounds a reaction area containing a cylindrical grid-like anode and a central ion collector which consists of a straight axial filament. An ion collector current reflecting the density of the gas in the reaction region is measured by a current meter while a gate voltage is kept between the ground voltage of the emitter layer and a higher anode voltage and is regulated in such a way that an anode current is kept constant. The emitter layer may consists of carbon nanotubes, diamond-like carbon, a metal or a mixture of metals or a semiconductor material, e.g., silicon which may be coated, e.g., with carbide or molybdenum. The emitter surface can, however, also be a portion of the inside surface of the side wall roughened by, e.g., chemical etching. The gate may be a grid or it may be made up of patches of metal film covering spacers distributed over the emitter area or a metal film covering an electron permeable layer placed on the em…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.