US3892989A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Convergent flow hollow beam X-ray gun construction
Assignee: KEVEX Corp FOSTER CITY CA A CORP OF
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Filing: 1973-05-09
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Granted: 1975-07-01
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Expires: 1993-05-09
Abstract
Abstract An X-ray generating tube characterized by grid means formed with narrow annular slits which serve to isolate the cathode from being influenced by the high voltage of the anode. According to one embodiment, a target formed as a hollow conical surface of revolution closed at one end forms an X-ray window at one end of the tube. According to another embodiment, the axis of the tube remains substantially unobstructed whereby X-rays generated from a conical surface of the type noted above are emitted at the end of the tube disposed opposite the target end. Another embodiment combines the advantages of the first named and last named embodiment by utilizing concentrically oriented coaxially disposed electron beam control elements formed with a narrow annular slit for passing electrons radially into the axial region of the tube.
Inventors
- 👤 Nicholas M Gralenski
- 👤 George Wada
- 👤 David J Bates
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:52
CPC Classifications
H; H01; H01J; H01J35/00; H01J35/02; H01J35/14; H01J35/147
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
158 words
In an X-ray generating device of a type employing an evacuated enclosure and a target of material disposed therein to be struck by high energy electrons to develop X-rays, the improvement comprising a cathode having an electron-emitting portion adapted to be charged negatively with respect to said target to create an annular, hollow beam of electrons for impinging upon said target, said target being formed with a closed conical surface, said surface converging in a direction leading away from said cathode, means responsive to a potential applied thereto for focusing said beam onto said surface, a control element and means coupled to said control element for continuously varying the potential thereof to cause said flow of electrons to cause said annular beam to impinge upon said surface with a varying diameter in response to variations in said potential of the last named means, and a window formed to pass Xrays out of said enclosure axially of said beam.
Claim 2
Dependent Claim
158 words
In an X-ray generating device of a type employing an evacuated enclosure and a target of material disposed therein to be struck by high energy electrons to develop X-rays, the improvement comprising a cathode having an electron-emitting portion adapted to be charged negatively with respect to said target to create an annular, hollow beam of electrons for impinging upon said target, said target being formed with a closed conical surface, said surface converging in a direction leading away from said cathode, means responsive to a potential applied thereto for focusing said beam onto said surface, a control element and means coupled to said control element for continuously varying the potential thereof to cause said flow of electrons to cause said annular beam to impinge upon said surface with a varying diameter in response to variations in said potential of the last named means, and a window formed to pass Xrays out of said enclosure axially of said beam.
Claim 3
Dependent Claim
18 words
In an X-ray generating device according to claim 1 further including means forming said window via said target.
Claim 4
Dependent Claim
40 words
In an X-ray generating device according to claim 1 wherein said target comprises an X-ray transmissive layer of material supported by a heat conductive X-ray transmissive member therebehind whereby to form said window axially of said beam via said member.
Claim 5
Dependent Claim
238 words
In an X-ray generating device of a type employing a target of material disposed to be struck by high energy electrons to develop X-rays, the improvement comprising a cathode having an electron-emitting portion adapted to be charged negatively with respect to said target to create a flow of electrons from said portion to said target, said target being formed with a closed conical surface portion and converging in a direction leading away from said cathode, a focusing grid element and means for applying a potential thereto for focusing said flow of electrons primarily onto said closed conical surface, annular grid means disposed adjacent said cathode and across said flow of electrons and including a slit therearound for passing said flow of electrons therethrough to move in a path leading toward said target, said slit being sufficiently narrow and said cathode portion being spaced sufficiently therebehind so as to inhibit the potential of said target from influencing said electron emission from said cathode portion, an annular control element encircling said flow of electrons, and means coupled to said control element for varying the potential thereof to cause said focused flow of electrons to provide an annular beam impinging primarily upon said surface with a varying diameter in response to variations in said potential of said last named means, said annular grid means and control element being each comprised of an annular member coaxially disposed with respect to each other.
Claim 6
Dependent Claim
238 words
In an X-ray generating device of a type employing a target of material disposed to be struck by high energy electrons to develop X-rays, the improvement comprising a cathode having an electron-emitting portion adapted to be charged negatively with respect to said target to create a flow of electrons from said portion to said target, said target being formed with a closed conical surface portion and converging in a direction leading away from said cathode, a focusing grid element and means for applying a potential thereto for focusing said flow of electrons primarily onto said closed conical surface, annular grid means disposed adjacent said cathode and across said flow of electrons and including a slit therearound for passing said flow of electrons therethrough to move in a path leading toward said target, said slit being sufficiently narrow and said cathode portion being spaced sufficiently therebehind so as to inhibit the potential of said target from influencing said electron emission from said cathode portion, an annular control element encircling said flow of electrons, and means coupled to said control element for varying the potential thereof to cause said focused flow of electrons to provide an annular beam impinging primarily upon said surface with a varying diameter in response to variations in said potential of said last named means, said annular grid means and control element being each comprised of an annular member coaxially disposed with respect to each other.
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) | 1978-06-30 | 1978-12-30 | 1979-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-30 | 1982-12-30 | 1983-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-30 | 1986-12-30 | 1987-07-01 | $7700.00 | Window Closed / Lapsed |