Method of determining the x-ray limit of an ion gauge
US4302679A · kind A · utility
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2References
3Claims
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Assignee
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Key dates
| Filing date | Aug 7, 1979 |
| Grant date | Nov 24, 1981 |
| Priority date | — |
| Expiry date | Aug 7, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J41/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An ion gauge having a reduced "x-ray limit" and means for measuring that limit. The gauge comprises an ion gauge of the Bayard-Alpert type having a short collector and having means for varying the grid-collector voltage. The "x-ray limit" (i.e. the collector current resulting from x-rays striking the collector) may then be determined by the formula: ##EQU1## where: I.sub.x ="x-ray limit", PA1 I.sub.l and I.sub.h =the collector current at the lower and higher grid voltage respectively; and, PA1 .alpha.=the ratio of the collector current due to positive ions at the higher voltage to that at the lower voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.