Patent US3700945A successfully refreshed from Google Patents.
US3700945A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High power pulsed electron beam
Assignee: United States Department of the Navy
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Filing: 1971-08-30
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Granted: 1972-10-24
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Expires: 1991-08-30
Abstract
Abstract Apparatus for generating a relativistic annular electron beam with a power in the 1010 watt range utilizing a solid conical cathode of blunted shape and a surrounding truncated anode. A high intensity, pulsed magnetic field guides and focuses the electrons emitted from roughened areas of the cathode by a cold field emission process to form the annular beam.
Inventors
- 👤 Mushe Friedman
- 👤 Michael G Ury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:25
CPC Classifications
H; H01; H01J; H01J23/00; H01J23/02; H01J23/06; H01J23/075; H01J1/00; H01J1/02; H01J1/30; H01J1/304; H01J3/00; H01J3/02; H01J3/021
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
178 words
Apparatus for producing a high power annular pulsed electron beam comprising, in combination, a cathode having a generally conicAl shape with its apex portion blunted, said cathode being of solid construction and made of a nonmagnetic, metallic material; an anode having a frusto-conical shape symmetrically positioned about said cathode such that the longitudinal axis of symmetry of said cathode and said anode are co-extensive; a magnetic coil surrounding said anode; means for coupling a high amplitude current pulse to said magnetic coil, the solid and conducting nature of said cathode preventing any appreciable penetration of this cathode by the pulsed magnetic field thereby produced and causing this magnetic field to be parallel to the slant surface of said cathode in the space between said cathode and said anode; and means for driving said cathode highly negative with respect to said anode when said magnetic field has reached its maximum intensity whereby electrons are emitted from said cathode in a cold emission process and thereafter deflected and focused by said magnetic field into a high-power, annular, pulsed electron beam.
Claim 2
Dependent Claim
178 words
Apparatus for producing a high power annular pulsed electron beam comprising, in combination, a cathode having a generally conicAl shape with its apex portion blunted, said cathode being of solid construction and made of a nonmagnetic, metallic material; an anode having a frusto-conical shape symmetrically positioned about said cathode such that the longitudinal axis of symmetry of said cathode and said anode are co-extensive; a magnetic coil surrounding said anode; means for coupling a high amplitude current pulse to said magnetic coil, the solid and conducting nature of said cathode preventing any appreciable penetration of this cathode by the pulsed magnetic field thereby produced and causing this magnetic field to be parallel to the slant surface of said cathode in the space between said cathode and said anode; and means for driving said cathode highly negative with respect to said anode when said magnetic field has reached its maximum intensity whereby electrons are emitted from said cathode in a cold emission process and thereafter deflected and focused by said magnetic field into a high-power, annular, pulsed electron beam.
Claim 3
Dependent Claim
39 words
In an arrangement as defined in claim 1 wherein said cathode has a circumferential portion of its outer surface roughened so as to enhance electron emission therefrom when said cathode is driven highly negative with respect to said anode.
Claim 4
Dependent Claim
29 words
In an arrangement as defined in claim 1, wherein said anode is made of thin metallic material so as to permit the magnetic field to penetrate it without distortion.
Claim 5
Dependent Claim
35 words
In an arrangement as defined in claim 1, a cylindrical screen, one end of said screen being connected to the apex portion of said anode and maintained at the same electrical potential as said anode.
Claim 6
Dependent Claim
41 words
In an arrangement as defined in claim 1, means for establishing a constant magnetic field along the direction of travel of said annular electron beam thereby to maintain said beam in focus as it passes down through an evacuated drift space.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |