Patent US3883761A successfully refreshed from Google Patents.
US3883761A
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Electrostatic extraction method and apparatus for cyclotrons
Assignee: Cyclotron Corp
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Filing: 1972-12-08
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Granted: 1975-05-13
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Expires: 1992-12-08
Abstract
Abstract A method and apparatus for electrostatically extracting high beam currents at improved energy from small diameter, high magnetic field cyclotrons by deflecting particles from their trajectory within an electrostatic field traversing an extraction channel wherein magnetic material immediately adjacent to the inside of at least a portion of the channel first reduces the fringe field and then reverses its normal gradient to assist in extraction and to focus the extracted beam radially with respect to the center of the cyclotron.
Inventors
- 👤 George O Hendry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:03
CPC Classifications
H; H05; H05H; H05H13/00; H05H7/00; H05H7/10
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
130 words
Improved apparatus for electrostatically deflecting a beam of charged particles at an extraction radius in the fringe magnetic field of an isochronous cyclotron comprising means defining an electrostatic field across a deflection channel at the extraction radius, the location of said field increasing in radius with respect to the center of the cyclotron; and magnetic material positioned inside and adjacent to at least a portion of said channel to reduce the cyclotron fringe field at the channel and to focus the beam of charged particles radially with respect to the center of the cyclotron, by concentrating the lines of magnetic force of said fringe field inwardly of but immediately adjacent to said channel to reduce said fringe field and then to reverse the normally decreasing field gradient in said channel.
Claim 2
Dependent Claim
130 words
Improved apparatus for electrostatically deflecting a beam of charged particles at an extraction radius in the fringe magnetic field of an isochronous cyclotron comprising means defining an electrostatic field across a deflection channel at the extraction radius, the location of said field increasing in radius with respect to the center of the cyclotron; and magnetic material positioned inside and adjacent to at least a portion of said channel to reduce the cyclotron fringe field at the channel and to focus the beam of charged particles radially with respect to the center of the cyclotron, by concentrating the lines of magnetic force of said fringe field inwardly of but immediately adjacent to said channel to reduce said fringe field and then to reverse the normally decreasing field gradient in said channel.
Claim 3
Dependent Claim
54 words
The apparatus of claim 1 wherein the means defining an electrostatic field includes a thin curved septum and a curved deflector electrode which define between them a shaped deflection channel with a high electric field gradient across it and the magnetic material is positioned along inside of at least a portion of said septum.
Claim 4
Dependent Claim
100 words
An improved method for electrostatically deflecting a beam of charged particles at an extraction radius in the fringe magnetic field of an isochronous cyclotron comprising the steps of defining an electrostatic field within a channel at the extraction radius which increases in radius with respect to the center of the cyclotron; and placing a magnetic member along at least a portion of said channel to concentrate the lines of magnetic force of said fringe field inwardly of but immediately adjacent to said channel to reduce said fringe field and then to reverse the normally decreasing field gradient in said channel.
Claim 5
Dependent Claim
100 words
An improved method for electrostatically deflecting a beam of charged particles at an extraction radius in the fringe magnetic field of an isochronous cyclotron comprising the steps of defining an electrostatic field within a channel at the extraction radius which increases in radius with respect to the center of the cyclotron; and placing a magnetic member along at least a portion of said channel to concentrate the lines of magnetic force of said fringe field inwardly of but immediately adjacent to said channel to reduce said fringe field and then to reverse the normally decreasing field gradient in said channel.
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) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |