US4687936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
In-line beam scanning system
Assignee: Varian Medical Systems Inc
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Filing: 1985-12-17
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Granted: 1987-08-18
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Expires: 2005-12-17
Abstract
Abstract A system for scanning a beam of charged-particles across a target is described which compensates for energy dispersion in the beam. A time-varying magnet with circular pole pieces is used to sweep the beam left to right. Two wedge-shaped magnet dipoles, one on each side of the center line are used to bend the beam parallel to the center line and compensate for beam energy dispersion.
Inventors
- 👤 Raymond D. McIntyre
- 👤 Karl L. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:20
CPC Classifications
H; H01; H01J; H01J3/00; H01J3/26; H01J3/28; H01J3/32; G; G21; G21K; G21K1/00; G21K1/08; G21K1/093; G21K5/00; G21K5/10; H01J33/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
258 words
A system for scanning a charged-particle beam along a scan path and controlling the energy of the beam comprising: a means for detecting a charged-particle beam pulse amplitude as the beam passes along a first line; a means for imposing a time-varying magnetic dipole field across a charged-particles beam after the beam has passed through said means for detecting a beam pulse amplitude, whereby the beam can be deflected in a beam plane to either side of the first line; a means for imposing a time-fixed dipole magnetic field on the beam after the beam has passed through said means for imposing a time-varying magnetic field, said means for imposing a time-fixed dipole magnetic field including means for imposing a first and a second wedge-shaped regions of magnetic field perpendicular to said beam plane, said first wedge-shaped region of magnetic field being of opposite polarity to said second wedge-shaped region of magnetic field, said first and second wedge-shaped regions of magnetic field being symmetrically positioned on either side of the first line whereby the beam direction or energy dispersion introduced at said means for imposing a time-varying magnetic dipole field is offset by focussing in said wedge-shaped regions of magnetic field; charged-particle detector means located along the path of the beam after passing through the time-fixed magnetic dipole field; and signal processing means for comparing a signal from said charged-particle detector means to a signal from said means for detecting a charged-particle pulse amplitude whereby the output from said signal processing means is used to control beam energy.
Claim 2
Independent Claim
258 words
A system for scanning a charged-particle beam along a scan path and controlling the energy of the beam comprising: a means for detecting a charged-particle beam pulse amplitude as the beam passes along a first line; a means for imposing a time-varying magnetic dipole field across a charged-particles beam after the beam has passed through said means for detecting a beam pulse amplitude, whereby the beam can be deflected in a beam plane to either side of the first line; a means for imposing a time-fixed dipole magnetic field on the beam after the beam has passed through said means for imposing a time-varying magnetic field, said means for imposing a time-fixed dipole magnetic field including means for imposing a first and a second wedge-shaped regions of magnetic field perpendicular to said beam plane, said first wedge-shaped region of magnetic field being of opposite polarity to said second wedge-shaped region of magnetic field, said first and second wedge-shaped regions of magnetic field being symmetrically positioned on either side of the first line whereby the beam direction or energy dispersion introduced at said means for imposing a time-varying magnetic dipole field is offset by focussing in said wedge-shaped regions of magnetic field; charged-particle detector means located along the path of the beam after passing through the time-fixed magnetic dipole field; and signal processing means for comparing a signal from said charged-particle detector means to a signal from said means for detecting a charged-particle pulse amplitude whereby the output from said signal processing means is used to control beam energy.
Claim 3
Dependent Claim
57 words
A system as in claim 1 wherein said charged-particle detector means includes matched pairs of charged-particle detector means located equidistant and symmetrically on either side of the beam plane and said signal processing means compares an average signal from said matched pairs of charged-particle detector means to a signal from means for detecting a charged-particle pulse amplitude.
Claim 4
Dependent Claim
43 words
A system as in claim 2 wherein said pairs of charged-particle detector means cover a maximum scan width of the ion beam whereby to prevent said signal from said charged-particle detector means from being a function of beam position along said scan path.
Claim 5
Independent Claim
260 words
A system for scanning a charged-particle beam along a scan path and controlling the energy of the beam comprising: a means for detecting a charged-particle beam pulse amplitude as the beam passes along a first line; a means for imposing a time-varying magnetic dipole field across a charged-particle beam after the beam has passed through said means for detecting a beam pulse amplitude, whereby the beam can be deflected in a beam plane to either side of the first line; a means for imposing a time-fixed dipole magnetic field on the beam after the beam has passed through said means for imposing a time-varying magnetic field, said means for imposing a time-fixed dipole magnetic field including means for imposing a first and a second wedged-shaped regions of magnetic field of perpendicular to said beam plane, said first wedge-shaped region of magnetic field being of opposite polarity to said second wedge-shaped region of magnetic field, said first and second wedge-shaped regions of magnetic field being symmetrically positioned on either side of the first line whereby the beam direction or energy dispersion introduced at said means for imposing a time-varying magnetic dipole field is offset by focussing in said wedge-shaped regions of magnetic field; charged-particle detector means located along the path of the beam after passing through the time-fixed magnetic dipole field; and signal processing means for comparing a signal from said charged-particle detector means to a signal from said means for imposing a time-varying magnetic dipole field whereby the output from said signal processing means is used to control beam energy.
Claim 6
Independent Claim
260 words
A system for scanning a charged-particle beam along a scan path and controlling the energy of the beam comprising: a means for detecting a charged-particle beam pulse amplitude as the beam passes along a first line; a means for imposing a time-varying magnetic dipole field across a charged-particle beam after the beam has passed through said means for detecting a beam pulse amplitude, whereby the beam can be deflected in a beam plane to either side of the first line; a means for imposing a time-fixed dipole magnetic field on the beam after the beam has passed through said means for imposing a time-varying magnetic field, said means for imposing a time-fixed dipole magnetic field including means for imposing a first and a second wedged-shaped regions of magnetic field of perpendicular to said beam plane, said first wedge-shaped region of magnetic field being of opposite polarity to said second wedge-shaped region of magnetic field, said first and second wedge-shaped regions of magnetic field being symmetrically positioned on either side of the first line whereby the beam direction or energy dispersion introduced at said means for imposing a time-varying magnetic dipole field is offset by focussing in said wedge-shaped regions of magnetic field; charged-particle detector means located along the path of the beam after passing through the time-fixed magnetic dipole field; and signal processing means for comparing a signal from said charged-particle detector means to a signal from said means for imposing a time-varying magnetic dipole field whereby the output from said signal processing means is used to control beam energy.
Claim 7
Dependent Claim
71 words
A system as in claim 4 wherein said charged-particle detector means includes a charged-particle collector located in the scan plane but outside a normal scan range and wherein a signal from said charged-particle collector is obtained by momentarily extending the scan range and wherein said signal processing means compares the timing of a signal from said charged-particle collector to said signal from said means for imposing a time-varying magnetic dipole field.
Claim 8
Dependent Claim
55 words
A system as in claim 4 wherein said charged-particle detector means includes a charged-particle detector located within the normal scan range and outside the scan plane and wherein said signal processing means compares the timing of a signal from said charged-particle detector to said signal from said means for imposing a time-varying magnetic dipole field.
Claim 9
Independent Claim
178 words
A system for scanning a charged-particle beam along a scan path comprising: a means for imposing a time-varying magnetic dipole field across a charged-particle beam after the beam has passed through a means for detecting a beam pulse amplitude, whereby the beam can be deflected in a beam plane to either side of the first line; and a means for imposing a time-fixed dipole magnetic field on the beam after the beam has passed through said means of imposing a time-varying magnetic field, said means for imposing a time-fixed dipole magnetic field including means for imposing a first and a second wedge-shaped regions of magnetic field perpendicular to said beam plane, said first wedge-shaped region of magnetic field being of opposite polarity to said second wedge-shaped region of magnetic field, said first and second wedge-shaped region of magnetic field being symmetrically positioned on either side of the first line whereby the beam direction or energy dispersion introduced at said means for imposing a time-varying magnetic dipole field is offset by focussing in said wedge-shaped regions of magnetic field.
Claim 10
Independent Claim
178 words
A system for scanning a charged-particle beam along a scan path comprising: a means for imposing a time-varying magnetic dipole field across a charged-particle beam after the beam has passed through a means for detecting a beam pulse amplitude, whereby the beam can be deflected in a beam plane to either side of the first line; and a means for imposing a time-fixed dipole magnetic field on the beam after the beam has passed through said means of imposing a time-varying magnetic field, said means for imposing a time-fixed dipole magnetic field including means for imposing a first and a second wedge-shaped regions of magnetic field perpendicular to said beam plane, said first wedge-shaped region of magnetic field being of opposite polarity to said second wedge-shaped region of magnetic field, said first and second wedge-shaped region of magnetic field being symmetrically positioned on either side of the first line whereby the beam direction or energy dispersion introduced at said means for imposing a time-varying magnetic dipole field is offset by focussing in said wedge-shaped regions of magnetic field.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-17 | 1991-02-16 | 1991-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-17 | 1995-02-16 | 1995-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-17 | 1999-02-16 | 1999-08-18 | $7700.00 | Window Closed / Lapsed |