US3966409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nuclear magnetometers for earth's field measurements based on dynamic polarization of nuclei and free radical substance for use therein
Assignee: Ministry of Natural Resources and Wildlife
•
Filing: 1974-09-09
•
Granted: 1976-06-29
•
Expires: 1994-09-09
Abstract
Abstract A free radical substance for use in a suitable solvent as the sample material in nuclear dynamic polarization type magnetometers which is a free radical substance of the oxazolidine group wherein the radicals R 1 and R 2 are chain radicals of the type --(CH 2 ) n CH 3 , wherein n varies from 0 to 2. It has been found that the free radical 2,2,4,4, tetramethyl oxazolidine-3-oxyl has outstanding characteristics for this purpose.
Inventors
- 👤 Ivan Hrvoic
- 👤 Kresimir Humski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:40
CPC Classifications
C; C07; C07D; C07D263/00; C07D263/02; C07D263/04; G; G01; G01R; G01R33/00; G01R33/20; G01R33/24; Y; Y10; Y10T; Y10T436/00; Y10T436/24
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
176 words
A method of measuring weak magnetic fields comprising: a. placing in the magnetic field to be measured, a sample of a chemical substance made up of an assembly of nuclei with magnetic moments different from zero, the transition energy between the two adjacent energy states of nuclear magnetic moments being strictly proportional to the applied magnetic field and an assembly of unpaired electrons with unpaired spin and magnetic moments, said nuclear and electron magnetic moments being coupled by dipolar or scalar coupling or both, the said unpaired electrons in the sample being provided by a free radical chemical substance of the oxazolidine group ##EQU1## wherein the radicals R 1 and R 2 are chain radicals of the type --(CH 2 ) n CH 3 , where n varies from 0 to 2, b. saturating with a strong RF magnetic field of frequency close to the electron energy transition, the said electron transitions producing a strong dynamic polarization of nuclear magnetic moments, and c. detecting and measuring by electrical means the transition energy states of nuclear moments.
Claim 2
Independent Claim
176 words
A method of measuring weak magnetic fields comprising: a. placing in the magnetic field to be measured, a sample of a chemical substance made up of an assembly of nuclei with magnetic moments different from zero, the transition energy between the two adjacent energy states of nuclear magnetic moments being strictly proportional to the applied magnetic field and an assembly of unpaired electrons with unpaired spin and magnetic moments, said nuclear and electron magnetic moments being coupled by dipolar or scalar coupling or both, the said unpaired electrons in the sample being provided by a free radical chemical substance of the oxazolidine group ##EQU1## wherein the radicals R 1 and R 2 are chain radicals of the type --(CH 2 ) n CH 3 , where n varies from 0 to 2, b. saturating with a strong RF magnetic field of frequency close to the electron energy transition, the said electron transitions producing a strong dynamic polarization of nuclear magnetic moments, and c. detecting and measuring by electrical means the transition energy states of nuclear moments.
Claim 3
Dependent Claim
46 words
A method of measuring weak magnetic fields as in claim 1 wherein the said unpaired electrons in the sample are provided by a free radical chemical substance of the oxazolidine group where R.sub. 1 = R.sub. 2 = CH 3 giving the radical (2,2,4,4, tetramethyl oxazolidine-3-oxyl).
Claim 4
Dependent Claim
24 words
A method of measuring weak magnetic fields as in claim 1 wherein the said nuclei are protons in an organic solvent rich in hydrogen.
Claim 5
Dependent Claim
18 words
A method of measuring weak magnetic fields as in claim 3 wherein the organic solvent is methyl hydrate.
References Cited (Backward Citations)
US3489522A
Cited
US3668214A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-29 | 1979-12-29 | 1980-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-29 | 1983-12-29 | 1984-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-29 | 1987-12-29 | 1988-06-29 | $7700.00 | Window Closed / Lapsed |