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US3585494A
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Electron spin echo system having a pulsed preparation magnetic field applied to the sample
Assignee: Westinghouse Electric Corp
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Filing: 1969-06-11
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Granted: 1971-06-15
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Expires: 1989-06-11
Abstract
Abstract Method and apparatus for achieving adiabatic demagnetization of an electron spin echo sample for enhancing the dynamic range and operable repetition rate of electron spin echoes by applying a ''''preparation'''' pulsed magnetic field of a predetermined field strength and direction to the sample located in a resonant cavity prior to the application of a pair of successive microwave pulses orthogonally to a relatively smaller static, unidirectional magnetic field so that a spin echo signal is produced before thermal equilibrium of the sample is reached. The static magnetic field is established either after or concurrently with the pulsed magnetic field and in the same direction.
Inventors
- 👤 Donald A Bozanic
- 👤 Dickron Mergerian
- 👤 Ronald W Minarik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:07
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/60
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
203 words
An electron spin echo system comprising in combination: RF generator means for generating a first and a second pulse of RF energy separated by a predetermined time interval; a resonant cavity; a paramagnetic spin echo sample located in said cavity; circuit means coupling said RF generator means to said cavity for generating a spin echo signal when said first and said second pulse of RF energy are applied to said sample; means for generating a static unidirectional magnetic field through said spin echo sample at least while applying said first and said second RF pulse and generating said spin echo signal, said static magnetic field being directed through said sample substantially transverse to the direction of the application of said first and second RF pulse; and preparation means for generating a unidirectional magnetic field of a predetermined strength and duration in the same direction as said static magnetic field through said echo sample prior to the application of said first and said second RF pulse, said first and second RF pulses being applied in a time which is short relative to the spin-lattice relaxation time of the spin echo sample resulting from the discontinuance of the magnetic field generated by said preparation means.
Claim 2
Dependent Claim
203 words
An electron spin echo system comprising in combination: RF generator means for generating a first and a second pulse of RF energy separated by a predetermined time interval; a resonant cavity; a paramagnetic spin echo sample located in said cavity; circuit means coupling said RF generator means to said cavity for generating a spin echo signal when said first and said second pulse of RF energy are applied to said sample; means for generating a static unidirectional magnetic field through said spin echo sample at least while applying said first and said second RF pulse and generating said spin echo signal, said static magnetic field being directed through said sample substantially transverse to the direction of the application of said first and second RF pulse; and preparation means for generating a unidirectional magnetic field of a predetermined strength and duration in the same direction as said static magnetic field through said echo sample prior to the application of said first and said second RF pulse, said first and second RF pulses being applied in a time which is short relative to the spin-lattice relaxation time of the spin echo sample resulting from the discontinuance of the magnetic field generated by said preparation means.
Claim 3
Dependent Claim
26 words
The invention as defined by claim 1 wherein said RF generator means comprises means for producing a first and a second pulse of microwave frequency energy.
Claim 4
Dependent Claim
76 words
The invention as defined by claim 1 and additionally including a timing circuit coupled to said RF generator means and said preparation means for synchronously applying a pulsed magneTic field to said spin echo sample in relation to the application of said first and said second pulse so that the first and second pulse occur at a predetermined time during the spin-lattice relaxation time of the sample resulting from the application of said pulsed magnetic field.
Claim 5
Dependent Claim
47 words
The invention as defined by claim 3 wherein said means for generating said pulsed magnetic field additionally comprises a pulse generator and magnetic coil means coupled together to said timing circuit means whereby said pulse generator means produces a current pulse for energizing said magnetic coil means.
Claim 6
Dependent Claim
54 words
The invention as defined by claim 4 wherein said RF generator means comprises microwave generator means for producing a first and a second pulse of microwave frequency energy and wherein said means for generating said static unidirectional magnetic field is also operated during the operation of said means for generating said pulsed magnetic field.
Claim 7
Dependent Claim
30 words
The invention as defined by claim 5 wherein the magnetic field of said preparation means comprises a pulsed magnetic field having an amplitude substantially greater than said static magnetic field.
Claim 8
Dependent Claim
58 words
The invention as defined by claim 3 wherein said RF generator means comprises a CW microwave frequency generator, and RF switch coupled to said CW microwave frequency generator, and a double pulse generator circuit coupled between said RF switch and said timing circuit for actuating said RF switch to produce said first and second pulse of RF energy.
Claim 9
Independent Claim
122 words
The method of increasing the dynamic range and repetition rate of a spin echo signal comprising the steps of: generating a first unidirectional magnetic field of a predetermined strength and duration; positioning a spin echo sample within said first unidirectional field; applying a static unidirectional magnetic field in the same direction as said first magnetic field to said sample at least in the absence of said first magnetic field; and applying a first and a second pulse of RF energy to said sample substantially transverse to said static magnetic field after the termination of said first unidirectional magnetic field but within a predetermined time relative to the spin-relaxation time of the sample resulting from the termination of said first unidirectional magnetic field.
Claim 10
Independent Claim
122 words
The method of increasing the dynamic range and repetition rate of a spin echo signal comprising the steps of: generating a first unidirectional magnetic field of a predetermined strength and duration; positioning a spin echo sample within said first unidirectional field; applying a static unidirectional magnetic field in the same direction as said first magnetic field to said sample at least in the absence of said first magnetic field; and applying a first and a second pulse of RF energy to said sample substantially transverse to said static magnetic field after the termination of said first unidirectional magnetic field but within a predetermined time relative to the spin-relaxation time of the sample resulting from the termination of said first unidirectional magnetic field.
Claim 11
Dependent Claim
37 words
The method as defined by claim 8 wherein said step of generating said first unidirectional magnetic field further comprises generating a pulse of magnetic energy having substantially greater magnitude than the magnitude of said static magnetic field.
Claim 12
Dependent Claim
30 words
The method as defined by claim 9 and wherein said step of applying said static magnetic field additionally comprises applying said static magnitude concurrently with said first unidirectional magnetic field.
References Cited (Backward Citations)
US2700147A
Cited
US3275931A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |