Dual ion source
AssigneeLeybold Inficon, Inc.
InventorDavid H. Holkeboer
Life of this patent
Estimating the term…
Abstract
A dual beam ion source comprises an ion volume in an ion chamber, an ion collector, and two identical ion accelerators. One ion accelerator accelerates a first, "test" ion stream from the ion volume in a first direction and directs it to the ion collector where it can be directly measured. The second ion accelerator accelerates a second, "utilizable" ion stream from the ion volume in a second direction. By directly measuring the ion current (caused by the first, "test" ion stream) at the ion collector, either or both the total ion pressure of the gas within the ion volume, and the magnitude of the second, "utilizable" ion stream, can be calculated.
Claims7
An apparatus for determining a total ion pressure of a gas, comprising:
- an ion chamber plate defining an ionization chamber and a single ion volume therein;
- ionization means for ionizing molecules of said gas within said ionization chamber to produce first and second ion streams within said single ion volume;
- first and second ion accelerators;
- an ion collector;
- an analyzer;
- means for establishing a first voltage difference between said ion chamber plate and said first ion accelerator, such that said first ion stream is directed toward said ion collector;
- means for establishing a second voltage difference between said ion chamber plate and said second ion accelerator, such that said second ion stream is directed toward said analyzer;
- means for collecting said first ion stream at said ion collector;
- means for measuring a reference current produced by said first ion stream at said ion collector;
- and
- means, using said reference current, for calculating said total ion pressure of said gas within said single ion volume.
An apparatus for determining a total ion pressure of a gas sample, comprising:
- emission means for emitting a plurality of electrons;
- an anode having first and second openings therein defining first and second ionization regions;
- a first portion of said plurality of electrons passing through said first opening to produce a first ion stream in said first ionization region;
- a second portion of said plurality of electrons passing through said second opening to produce a second ion stream in said second ionization region;
- first and second ion focus plates;
- a total pressure ion collector;
- a gas analyzer;
- means for establishing a first voltage difference between said anode and said first ion focus plate such that said first ion stream is directed to said total pressure ion collector;
- means for establishing a second voltage difference between said anode and said second focus plate such that said second ion stream is directed to said gas analyzer;
- means, responsive to said first ion stream impinging on said total pressure ion collector, for determining said total ion pressure of said gas sample;
- means, responsive to said second ion stream received in said gas analyzer, for determining at least one partial pressure of said gas sample;
- and
- said first and second ionization regions being in close proximity such that said total partial pressure and said at least one partial pressure are determined from said same gas sample.
Dependencies are inferred from the claim text.