US4445102A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnet pole tips
Assignee: United States Department of Energy
•
Filing: 1981-11-19
•
Granted: 1984-04-24
•
Expires: 2001-11-19
Abstract
Abstract An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.
Inventors
- 👤 Craig E. Thorn
- 👤 Chellis Chasman
- 👤 Anthony J. Baltz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:05
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/06; H01F7/20; H01F7/202
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
125 words
A magnet having reduced fringing and improved stability comprising a pair of spaced, opposed, magnetic poles, said poles being symmetrical about the mid-plane of the gap between them, each of said poles further comprising a pole root formed from a low reluctance material and a pole tip also formed from a low reluctance material, said pole tips being attached to the central portion of said pole roots, whereby said pole tips define the gap between said poles and at least one portion of said pole tips being separated from said pole roots, said separation beginning at a predetermined distance from the center of said pole and the amount of said separation being an increasing function of radial distance and independent of azimuth within said portion.
Claim 2
Dependent Claim
125 words
A magnet having reduced fringing and improved stability comprising a pair of spaced, opposed, magnetic poles, said poles being symmetrical about the mid-plane of the gap between them, each of said poles further comprising a pole root formed from a low reluctance material and a pole tip also formed from a low reluctance material, said pole tips being attached to the central portion of said pole roots, whereby said pole tips define the gap between said poles and at least one portion of said pole tips being separated from said pole roots, said separation beginning at a predetermined distance from the center of said pole and the amount of said separation being an increasing function of radial distance and independent of azimuth within said portion.
Claim 3
Dependent Claim
30 words
A magnet as described in claim 1 wherein the width of said gap decreases with increasing radius in tlose portions wherein said pole tips are separated from said pole root.
Claim 4
Dependent Claim
14 words
A magnet as described in claims 1 or 2 wherein said function is linear.
Claim 5
Dependent Claim
36 words
A magnet as described in claims 1 or 2 wherein said pole tips each comprise a raised sector so that said gap is reduced between said raised sectors and said raised sectors comprise said separated portions.
Claim 6
Dependent Claim
33 words
A magnet as described in claim 4, wherein said pole tips have a multiple symmetry about the axis of said poles and comprise a plurality of raised sectors separated azimuthally by lower sectors.
Claim 7
Dependent Claim
34 words
A magnet as described in claim 5, wherein cleats are provided at the edges of said higher sectors and shims are provided at the edges of said lower sectors whereby fringing is further reduced.
Claim 8
Dependent Claim
40 words
A magnet as described in claims 1 or 2 wherein said magnet is an electromagnet and said poles are operatively associated with a magnet yoke and coil for the generation of a magnetic field in the gap between said poles.
Claim 9
Dependent Claim
38 words
A magnet as described in claim 6 wherein said magnet is an electromagnet and said poles are operatively associated with a magnet yoke and coil for the generation of a magnetic field in the gap between said poles.
Claim 10
Dependent Claim
11 words
An isochronous cyclotron comprising an electromagnet as described in claim 7.
Claim 11
Dependent Claim
11 words
An isochronous cyclotron comprising an electromagnet as described in claim 8.
References Cited (Backward Citations)
US3175131A
Cited
US3434085A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-04-24 | 1987-10-24 | 1988-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-24 | 1991-10-24 | 1992-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-24 | 1995-10-24 | 1996-04-24 | $7700.00 | Window Closed / Lapsed |