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US4611121A
Expired / Lapsed
US
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Magnet apparatus
Assignee: Daido Steel Co Ltd
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Filing: 1984-04-18
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Granted: 1986-09-09
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Expires: 2004-04-18
Abstract
Abstract Magnet apparatus for providing a magnetic field having a gradient in an operation chamber comprising a cylindrical permanent magnet surrounding an outer periphery of the operation chamber and having opposite ends and a hollow interior, and a subsidiary yoke at one of the ends, the subsidiary yoke having a cylindrical portion extending into the hollow interior. The subsidiary yoke can include a flange portion. The cylindrical portion is inserted through the flange portion and fixed thereto with bolts. The permanent magnet can be made of Ba-ferrite, Sr-ferrite or the like.
Inventors
- 👤 Masao Miyamura
- 👤 Osamu Tsukakoshi
- 👤 Yoshio Kamata
- 👤 Shoji Aiba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:30
CPC Classifications
H; H01; H01J; H01J27/00; H01J27/02; H01J27/022; H01J27/16
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
163 words
A permanent magnet apparatus for an ion source providing a magnetic field having a gradient in an operating chamber into which microwaves are introduced comprising a cylindrical permanent magnet having open ends and surrounding the outer walls of an operating chamber having a hollow interior and an open inlet end and an open outlet end, and a subsidiary yoke at one of the ends of said cylindrical magnet, the subsidiary yoke having a cylindrical portion extending into but not completely contained with said cylindrical magnet at said inlet end of said operating chamber and toward said outlet end substantially one half the length of said cylindrical magnet and in axial alignment with the axis of said cylindrical magnet and said operating chamber and intermediate said cylindrical magnet and said operating chamber, the outer diameter of said yoke being smaller than the inner diameter of said cylindrical magnet and means at the operating chamber inlet end of said cylindrical magnet for supporting said yoke.
Claim 2
Dependent Claim
163 words
A permanent magnet apparatus for an ion source providing a magnetic field having a gradient in an operating chamber into which microwaves are introduced comprising a cylindrical permanent magnet having open ends and surrounding the outer walls of an operating chamber having a hollow interior and an open inlet end and an open outlet end, and a subsidiary yoke at one of the ends of said cylindrical magnet, the subsidiary yoke having a cylindrical portion extending into but not completely contained with said cylindrical magnet at said inlet end of said operating chamber and toward said outlet end substantially one half the length of said cylindrical magnet and in axial alignment with the axis of said cylindrical magnet and said operating chamber and intermediate said cylindrical magnet and said operating chamber, the outer diameter of said yoke being smaller than the inner diameter of said cylindrical magnet and means at the operating chamber inlet end of said cylindrical magnet for supporting said yoke.
Claim 3
Dependent Claim
16 words
A magnet apparatus as claimed in claim 1, wherein the permanent magnet is made of Ba-ferrite.
Claim 4
Dependent Claim
16 words
A magnet apparatus as claimed in claim 1, wherein the permanent magnet is made of Sr-ferrite.
Claim 5
Dependent Claim
16 words
A magnet apparatus as claimed in claim 1, wherein the permanent magnet is made of alnico.
Claim 6
Dependent Claim
22 words
A magnet apparatus as claimed in claim 1, wherein the permanent magnet is made of such rare metal compounds as samarium cobalt.
Claim 7
Dependent Claim
23 words
A magnet apparatus as claimed is claim 1, wherein the operation chamber is a vacuum electric discharging chamber serving as an ion source.
Claim 8
Dependent Claim
30 words
A magnet apparatus as claimed in claim 1, wherein the subsidiary yoke comprises a flange portion and the cylindrical portion inserted through the flange portion and fixed thereto with bolts.
Claim 9
Dependent Claim
40 words
A magnet apparatus as claimed in claim 7 in which said cylindrical portion of said subsidiary yoke in said flange is adjustable for adjusting the extension of said cylindrical yoke in said cylindrical magnet toward said operating chamber outlet end.
References Cited (Backward Citations)
US2503173A
Cited
US4393333A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-08 | 1990-03-10 | 1990-09-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-08 | 1994-03-10 | 1994-09-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-08 | 1998-03-10 | 1998-09-09 | $7700.00 | Window Closed / Lapsed |