Patent US4048555A successfully refreshed from Google Patents.
US4048555A
Expired / Lapsed
US
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Spin resonance spectrometer and magnet structure
Assignee: AT&T Inc
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Filing: 1976-06-15
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Granted: 1977-09-13
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Expires: 1996-06-15
Abstract
Abstract A permanent magnet structure provides high fields (e.g., ˜ 4500 Gauss) with excellent uniformity (e.g., ± 3 Gauss) over a moderately large volume of the gap (e.g., approximately 20 percent of the gap diameter and gap width). This is accomplished by grinding away a portion of the permanent magnet material at the center of each face of the gap to form a depression, deepest at the center of the face. The magnet may include means for varying the gap width and a modulating coil for low frequency minor variation of the magnetic field. The magnet structure is used in conjunction with a 12 GHz self-excited spin resonance cavity to form a compact, portable electron spin resonance spectrometer.
Inventors
- 👤 Louis William Rupp, Jr.
- 👤 Walter Michael Walsh, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:48
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/02; H01F7/0273; H01F7/0278; G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/38; G01R33/383
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
148 words
A magnet structure comprising: a. a pair of coaxial permanent magnets, each of which is circularly symmetric about the common axis, and each of which possesses a first face and a a second face, the first faces of which are spaced from one another to form a gap free from domain magnetic material, the magnets being axially magnetized with poles of opposite polarity facing one another; and b. a housing including soft magnetic material in contact with the permanent magnets at the second face of each magnet, the housing holding the magnets in spaced relationship and providing a return path for magnetic flux around the gap characterized in that the first face of each permanent magnet forms an axial depression so shaped as to be monotonically deeper toward the axis, whereby the radial and axial uniformity of the magnetic field at the center of the gap is improved.
Claim 2
Dependent Claim
148 words
A magnet structure comprising: a. a pair of coaxial permanent magnets, each of which is circularly symmetric about the common axis, and each of which possesses a first face and a a second face, the first faces of which are spaced from one another to form a gap free from domain magnetic material, the magnets being axially magnetized with poles of opposite polarity facing one another; and b. a housing including soft magnetic material in contact with the permanent magnets at the second face of each magnet, the housing holding the magnets in spaced relationship and providing a return path for magnetic flux around the gap characterized in that the first face of each permanent magnet forms an axial depression so shaped as to be monotonically deeper toward the axis, whereby the radial and axial uniformity of the magnetic field at the center of the gap is improved.
Claim 3
Dependent Claim
30 words
A magnet structure of claim 1 in which the first faces are principally planar, with the depressions extending laterally to no more than one-half of the radius of the faces.
Claim 4
Dependent Claim
23 words
A magnet structure of claim 2 in which the depth of the depression is approximately one-twentieth of the diameter of the first faces.
Claim 5
Dependent Claim
19 words
A magnet structure of claim 1 in which the housing includes means for varying the width of the gap.
Claim 6
Dependent Claim
25 words
A magnet structure of claim 4 in which the housing includes a pair of coaxial modulation coils, one coil surrounding each of the permanent magnets.
Claim 7
Dependent Claim
40 words
A microwave spin resonance spectrometer comprising a magnet structure of claim 5 and a microwave spin resonance cavity structure so fixed in the gap that the sample space of the cavity is axially situated at the center of the gap.
Claim 8
Dependent Claim
16 words
A magnet structure of claim 1 in which the permanent magnets consist of Co 5 Sm.
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) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |