US3719856A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Impregnants for dispenser cathodes
Assignee: Individual
•
Filing: 1971-05-19
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Granted: 1973-03-06
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Expires: 1991-05-19
Abstract
Abstract A dispenser cathode suitable for use as an electron emitter for microwave tubes and the like. The dispenser cathode is constituted by a porous body of refractory material such as tungsten, impregnated with a fused mixture of barium oxide, and at least one oxide of a rare earth metal, such as holmium oxide, terbium oxide, thulium oxide or yttrium oxide.
Inventors
- 👤 O Koppius
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:43
CPC Classifications
H; H01; H01J; H01J1/00; H01J1/02; H01J1/13; H01J1/14; H01J1/20; H01J1/28
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
85 words
A thermionic dispenser cathode comprising a porous body of refractory metal having at least one surface position adapted to afford an electron-emission surface, and provided with a large number of small passageways connecting the interior of the body to said surface, and an impregnant disposed within said body and constituted by a fused mixture of barium oxide, yttrium oxide and at least one rare earth oxide selected from the class consisting of calcium oxide and scandium oxide in a mole ratio providing relatively high emission.
Claim 2
Dependent Claim
85 words
A thermionic dispenser cathode comprising a porous body of refractory metal having at least one surface position adapted to afford an electron-emission surface, and provided with a large number of small passageways connecting the interior of the body to said surface, and an impregnant disposed within said body and constituted by a fused mixture of barium oxide, yttrium oxide and at least one rare earth oxide selected from the class consisting of calcium oxide and scandium oxide in a mole ratio providing relatively high emission.
Claim 3
Dependent Claim
28 words
A cathode as set forth in claim 1, wherein said fused mixture consists essentially of 6 moles barium oxide, 1 mole calcium oxide, and 1 mole yttrium oxide.
Claim 4
Dependent Claim
28 words
A cathode as set forth in claim 1, wherein said fused mixture consists essentially of 6 moles barium oxide, 1 mole scandium oxide, and 1 mole yttrium oxide.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |