US3706920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tunnel electron emitter cathode
Assignee: United States Department of the Army
•
Filing: 1971-03-18
•
Granted: 1972-12-19
•
Expires: 1991-03-18
Abstract
Abstract A high efficiency tunnel electron emitter in which a unique emitting layer is applied to the insulator layer of a metalinsulator-emitting layer structure. The emitting layer consists of a low work function material such as cesium that is deposited directly on the insulator layer, a thin layer of a conductive metal that is deposited onto the cesium, and an exposed surface of the conductive metal having a layer of cesium oxide applied thereto to lower the work function. The amount of cesium deposited on the insulator layer is critical and is monitored for the proper amount during deposit.
Inventors
- 👤 Larry V Caldwell
- 👤 Brian S Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:11
CPC Classifications
B; B82; B82Y; B82Y10/00; H; H01; H01J; H01J1/00; H01J1/02; H01J1/34; H01J1/30; H01J1/312; H01J2201/00; H01J2201/34; H01J2201/342; H01J2201/3421; H01J2201/3425
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
23 words
An improved tunnel electron emitter as set forth in claim 1 wherein said surface treatment material is alternate layers Of cesium and oxygen.
Claim 2
Dependent Claim
25 words
An improved tunnel electron emitter as set forth in claim 2 wherein said metal emitter layer is aluminum and said insulator layer is aluminum oxide.
Claim 3
Dependent Claim
36 words
An improved tunnel electron emitter as set forth in claim 2 wherein said metal emitter layer is a semiconductor in which radiation exposed thereto produces free electrons in the conduction band that reach said insulator layer.
Claim 4
Dependent Claim
19 words
An improved tunnel electron emitter as set forth in claim 1 wherein said layer of conductive metal is antimony.
Claim 5
Dependent Claim
19 words
An improved tunnel electron emitter as set forth in claim 1 wherein said layer of conductive metal is silver.
Claim 6
Dependent Claim
19 words
An improved tunnel electron emitter as set forth in claim 1 wherein said layer of conductive material is gold.
References Cited (Backward Citations)
US2735049A
Cited
US3184636A
Cited
US3184659A
Cited
US3246200A
Cited
US3214629A
Cited
US3321659A
Cited
US3440499A
Cited
US3469184A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-19 | 1976-06-19 | 1976-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-19 | 1980-06-19 | 1980-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-19 | 1984-06-19 | 1984-12-19 | $7700.00 | Window Closed / Lapsed |