Vacuum gauge
AssigneeGranville-Phillips Company
InventorsDaniel G. Bills, Paul C. Arnold
Life of this patent
Estimating the term…
Abstract
A hot filament ionization gauge is provided with a very small diameter and/or very short collector to limit interception of X-ray flux. Suitable gauge sensitivity is achieved by additionally collecting ions at the collector support, which is shielded from the X-ray flux by a shield. Collection of ions by the shield is avoided by maintaining the shield at grid potential.
Claims17
An ionization vacuum gauge for measurement of ultra-high vacuum comprising:
- a supporting structure;
- a thermionic cathode rigidly connected to said supporting structure;
- a generally cylindrical grid-like anode enclosing a volume therein, said anode being rigidly connected to said supporting structure and disposed in electrical proximity to said cathode, said cathode being disposed external to said volume;
- a collector support rigidly connected to said supporting structure and disposed external to said volume;
- a collector extending from said collector support and protruding partially into said volume coaxially with said anode;
- and
- a shielding structure rigidly connected to said supporting structure and disposed external to said volume, between said collector support and said anode;
- said shielding structure having a cap-like shape for enclosing at least a portion of said collector support, and further being maintained at substantially the same potential as said anode;
- said collector being disposed within a first opening in an end portion of said shielding structure.
In an ionization gauge having a cathode for providing electrons and a grid for accelerating said electrons through a volume defined therein for ionizing a gas within said grid volume, the improvement comprising:
- an ion collector having a first part of relatively reduced area for protruding into said grid volume in a coaxial disposition relative to said grid;
- and a second part external to said grid volume for supporting said first part;
- means for shielding said second collector part from X-ray reflux produced at said grid;
- and
- means for maintaining said shielding means at a suitable potential relative to said grid;
- whereby positive ions are extracted from said volume and collected by said first and second collector parts.
Dependencies are inferred from the claim text.