US4345152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic lens
Assignee: Applied Biosystems Inc
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Filing: 1980-08-11
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Granted: 1982-08-17
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Expires: 2000-08-11
Abstract
Abstract A magnetic lens, useful as an objective lens in a focused charged particle beam generator, includes means for maintaining a constant thermal power dissipation independent of the field strength produced thereby.
Inventors
- 👤 Robert L. Gerlach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:39
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/02; H01J37/04; H01J37/10; H01J37/14; H01J37/141
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
129 words
A magnetic lens useful in a charged particle beam generator comprising: a base having an aperture therethrough, said aperture being axially aligned with the beam produced by said generator; means, for producing a controllable magnetic field in said aperture of said base and simultaneously maintaining a preselected thermal power dissipation independent of the strength of said magnetic field, said means being an electromagnetic coil concentric with said aperture and supported by said base; said coil including a pair of sub-coils the direction and magnitude of the currents of which are independently controllable; and means for controlling said magnetic field by varying the algebraic sum of said currents in said sub-coils; and means for maintaining said preselected thermal power dissipated by maintaining the absolute value sum of said currents constant.
Claim 2
Dependent Claim
129 words
A magnetic lens useful in a charged particle beam generator comprising: a base having an aperture therethrough, said aperture being axially aligned with the beam produced by said generator; means, for producing a controllable magnetic field in said aperture of said base and simultaneously maintaining a preselected thermal power dissipation independent of the strength of said magnetic field, said means being an electromagnetic coil concentric with said aperture and supported by said base; said coil including a pair of sub-coils the direction and magnitude of the currents of which are independently controllable; and means for controlling said magnetic field by varying the algebraic sum of said currents in said sub-coils; and means for maintaining said preselected thermal power dissipated by maintaining the absolute value sum of said currents constant.
Claim 3
Dependent Claim
36 words
A lens as claimed in claim 1 wherein said coil is a wound pair of adjacent wires, which wires are electrically insulated from each other whereby each wire of said pair defines one of said sub-coils.
Claim 4
Dependent Claim
35 words
A lens as claimed in claim 1 wherein said charged particle beam generator is operable over a range of beam energies; and said strength of said magnetic field is cooperatively adapted to said beam energies.
Claim 5
Dependent Claim
18 words
A lens as claimed in claim 1 or 2 wherein said sub-coils are electrically parallel with each other.
Claim 6
Dependent Claim
16 words
A lens as claimed in claim 1 or 2 where said sub-coils have substantially equal resistances.
Claim 7
Dependent Claim
38 words
A lens as claimed in claim 1 or 2 wherein the magnitude and direction of said currents in said sub-coils is electronically controlled via a circuit having as an input thereto a signal representative of said beam energy.
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) | 1985-08-16 | 1986-02-15 | 1986-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-16 | 1990-02-15 | 1990-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-16 | 1994-02-15 | 1994-08-17 | $7700.00 | Window Closed / Lapsed |