US3953789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of polarizing nuclei
Assignee: International Business Machines Corp
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Filing: 1974-11-20
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Granted: 1976-04-27
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Expires: 1994-11-20
Abstract
Abstract A method of polarizing nuclei having a long relaxation time in a solid in a high DC magnetic field. The solid also contains nuclei having a short relaxation time. The method involves the step of applying a high DC magnetic field to the solid. Then the solid is swept with a radio frequency field which excites the nuclei with a short relaxation time thereby resulting in the polarization of the nuclei having a long relaxation time.
Inventors
- 👤 Wiebren Sjoerd Veeman
- 👤 Costantino Sheldon Yannoni
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:32
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4641; H; H01; H01F; H01F13/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
92 words
A method for polarizing first nuclei having a long relaxation time in a solid in a high DC magnetic field where said solid contains first nuclei having long relaxation times and second nuclei having short relaxation times comprising the steps of applying a DC magnetic field having a strength above 1000 gauss to said solid, and sweeping said solid with a radio frequency field sufficient to excite a significant number of said second nuclei for a time which is at least as long as the time required to polarize said first nuclei.
Claim 2
Independent Claim
92 words
A method for polarizing first nuclei having a long relaxation time in a solid in a high DC magnetic field where said solid contains first nuclei having long relaxation times and second nuclei having short relaxation times comprising the steps of applying a DC magnetic field having a strength above 1000 gauss to said solid, and sweeping said solid with a radio frequency field sufficient to excite a significant number of said second nuclei for a time which is at least as long as the time required to polarize said first nuclei.
Claim 3
Dependent Claim
20 words
A method as described in claim 1 whereby the DC magnetic field has a magnitude between 10,000 and 75,000 gauss.
Claim 4
Dependent Claim
20 words
A method as described in claim 1 whereby said sweeping step is from a specific frequency to a higher frequency.
Claim 5
Dependent Claim
20 words
A method as described in claim 1 whereby said sweeping step is from a specific frequency to a lower frequency.
Claim 6
Dependent Claim
22 words
A method as described in claim 1 whereby said sweeping step is performed at a rate of from 0.9 to 2.8 MHz/sec.
Claim 7
Independent Claim
132 words
A method for polarizing nuclei having a long relaxation time in a solid in a high DC magnetic field where said solid contains first nuclei having long relaxation times and second nuclei having short relaxation times comprising the steps of applying a DC magnetic field having a strength above 1000 gauss to said solid, sweeping said solid with a radio frequency field sufficient to excite a significant number of said second nuclei for a time which is at least as long as the time required to polarize said first nuclei, and sweeping said solid at least one additional time with a radio frequency field sufficient to excite a significant number of said second nuclei for a time which is at least as long as the time required to polarize said first nuclei.
Claim 8
Independent Claim
132 words
A method for polarizing nuclei having a long relaxation time in a solid in a high DC magnetic field where said solid contains first nuclei having long relaxation times and second nuclei having short relaxation times comprising the steps of applying a DC magnetic field having a strength above 1000 gauss to said solid, sweeping said solid with a radio frequency field sufficient to excite a significant number of said second nuclei for a time which is at least as long as the time required to polarize said first nuclei, and sweeping said solid at least one additional time with a radio frequency field sufficient to excite a significant number of said second nuclei for a time which is at least as long as the time required to polarize said first nuclei.
Claim 9
Dependent Claim
22 words
A method as described in claim 6 whereby said second sweeping step is in the same direction as said first sweeping step.
Claim 10
Dependent Claim
22 words
A method as described in claim 6 whereby said second sweeping step is in a different direction from said first sweeping step.
References Cited (Backward Citations)
US3586743A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-27 | 1979-10-27 | 1980-04-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-27 | 1983-10-27 | 1984-04-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-27 | 1987-10-27 | 1988-04-27 | $7700.00 | Window Closed / Lapsed |