US3787760A
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Method and apparatus for recording spin resonance spectra using two sequences of rf exciting pulses
Assignee: Spectrospin AG
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Filing: 1972-06-02
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Granted: 1974-01-22
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Expires: 1992-06-02
Abstract
Abstract A method and apparatus are described for performing pulsed double resonance analyses such as selective saturation and homonuclear decoupling. The method comprises exciting the spins of a spin system in a sample with a series of RF pulses, exciting selected spins of the spin system with an RF signal having frequency components at approximately the Larmor (or resonance) frequencies of the selected spins, receiving the resultant free precession decay signals (or interferograms) of the resonant frequencies generated by the excitations, averaging a plurality of the free precession decay signals, and Fourier analyzing the mean value of the free precession decay signals to determine the spectral response. The excited spin system may be the set of spins associated with one type of nuclei in a sample. Apparatus for carrying out the method includes an RF generator and RF gate for producing a series of RF pulses to excite all the spins of the spin system, and at least one additional RF generator and RF gate for producing an RF oscillation to selectively excite only certain spins of the spin system.
Inventors
- 👤 T Keller
- 👤 W Tschopp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:31
CPC Classifications
G; G01; G01N; G01N24/00; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/46; G01R33/4616
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
101 words
A method for recording spin resonance spectra, comprising: exciting spins of one type of nuclei of a sample with a first sequence of RF pulses; exciting, with a second of RF pulses, selected ones of the spins excited with the first sequence of RF pulses; receiving, in the intervals between the pulses of the second sequence of RF pulses, an interferogram of the spins excited by the first and second sequences of RF pulses; storing selected amplitude values of at least one such interferogram; and Fourier analyzing amplitude values of at least one such interferogram to determine its component resonance frequencies.
Claim 2
Independent Claim
101 words
A method for recording spin resonance spectra, comprising: exciting spins of one type of nuclei of a sample with a first sequence of RF pulses; exciting, with a second of RF pulses, selected ones of the spins excited with the first sequence of RF pulses; receiving, in the intervals between the pulses of the second sequence of RF pulses, an interferogram of the spins excited by the first and second sequences of RF pulses; storing selected amplitude values of at least one such interferogram; and Fourier analyzing amplitude values of at least one such interferogram to determine its component resonance frequencies.
Claim 3
Dependent Claim
60 words
The method of claim 1 wherein the frequency spectrum of the second sequence of RF pulses is such that within the portion of the spin resonance spectrum that is recorded the spectrum of the second sequence of RF pulses has only component frequencies that approximately coincide with resonance frequencies of the spins excited by the second sequence of RF pulses.
Claim 4
Dependent Claim
25 words
The method of claim 1 wherein the carrier frequency of the second sequence of RF pulses coincides with the Larmor frequency of said selected spins.
Claim 5
Dependent Claim
33 words
The method of claim 1 wherein the pulse repetition rate of the second sequence of RF pulses is an integral multiple of the pulse repetition rate of the first sequence of RF pulses.
Claim 6
Dependent Claim
36 words
The method of claim 1 wherein the pulse repetition rate of the second sequence of RF pulses is in integral proportion to the rate at which the amplitude values of the interferogram are sampled for storage.
Claim 7
Dependent Claim
13 words
The method of claim 5 wherein the integral proportion is the ratio 1:1.
Claim 8
Dependent Claim
25 words
The method of claim 1 wherein the phase of the carrier frequency of the second sequence of RF pulses changes stochastically from pulse to pulse.
Claim 9
Dependent Claim
25 words
The method of claim 1 wherein the phase of the carrier frequency of the second sequence of RF pulses changes periodically from pulse to pulse.
Claim 10
Dependent Claim
29 words
The method of claim 1 wherein a plurality of second sequences of RF pulses are used, each of which has the same repetition rate but a different carrier frequency.
Claim 11
Dependent Claim
24 words
The method of claim 1 wherein the spacing of the pulses in the second sequence oF RF pulses changes stochastically from pulse to pulse.
Claim 12
Dependent Claim
24 words
The method of claim 1 wherein the spacing of the pulses in the second sequence of RF pulses changes periodically from pulse to pulse.
Claim 13
Dependent Claim
18 words
The method of claim 11 wherein the pulse repetition rate is modulated with at least one modulation frequency.
Claim 14
Dependent Claim
109 words
Apparatus for recording spin resonance spectra, comprising: means for exciting with a first sequence of RF pulses spins of one type of nuclei of a sample; means for exciting with a second sequence of RF pulses selected spins of the spins excited with the first sequence of RF pulses; means for receiving from the spins excited by the first and second sequences of RF pulses, in the intervals between the pulses of the second-sequence of RF pulses, resonance frequencies in the form of an interferogram; means for storing the amplitude values of at least one interferogram; and means for computing by Fourier analysis the resonance frequencies comprising the interferogram.
Claim 15
Dependent Claim
109 words
Apparatus for recording spin resonance spectra, comprising: means for exciting with a first sequence of RF pulses spins of one type of nuclei of a sample; means for exciting with a second sequence of RF pulses selected spins of the spins excited with the first sequence of RF pulses; means for receiving from the spins excited by the first and second sequences of RF pulses, in the intervals between the pulses of the second-sequence of RF pulses, resonance frequencies in the form of an interferogram; means for storing the amplitude values of at least one interferogram; and means for computing by Fourier analysis the resonance frequencies comprising the interferogram.
Claim 16
Dependent Claim
77 words
The apparatus of claim 13 wherein: the means for exciting spins with a first sequence of RF pulses comprises a first RF generator and a first pulse-controlled RF gate; the means for exciting selected spins with a second sequence of RF pulses comprises at least one additional RF generator and at least one additional pulse-controlled RF gate; and the means for storing the amplitude values of at least one interferogram comprises a signal averager and a memory.
Claim 17
Dependent Claim
23 words
The apparatus of claim 14 wherein the additional RF gate and the signal averager are connected to the output of a pulse generator.
Claim 18
Dependent Claim
19 words
The apparatus of claim 15 wherein a divider stage is located between the pulse generator and the signal averager.
Claim 19
Dependent Claim
36 words
The apparatus of claim 15 wherein the pulse generator supplies control pulses to the receiving means to permit it to receive resonance frequencies in the intervals between the pulses of the second sequence of RF pulses.
Claim 20
Dependent Claim
24 words
The apparatus of claim 15 wherein the pulse generator is connected to a variable frequency oscillator, whereby the pulse repetition rate may be varied.
Claim 21
Dependent Claim
20 words
The apparatus of claim 18 wherein the variable frequency oscillator is controlled by a control voltage from a voltage source.
Claim 22
Dependent Claim
18 words
The apparatus of claim 19 further comprising means for periodically varying the control voltage from a voltage source.
Claim 23
Dependent Claim
18 words
The apparatus of claim 19 further comprising means for stochastically varying the control voltage from a voltage source.
Claim 24
Dependent Claim
28 words
The apparatus of claim 14 wherein the first RF gate is coupled with the signal averager and is opened when the last address in the memory is reached.
Claim 25
Dependent Claim
20 words
The apparatus of claim 22 wherein a pulse shaper is located between the first RF gate and the signal averager.
Claim 26
Dependent Claim
173 words
Apparatus for recording spin resonance spectra comprising: means for directing at a sample of at least one type of nuclei a first sequence of RF pulses having a first carrier frequency and a first repetition rate to excite spins of one type of nuclei; means for directing at the sample a second sequence of RF pulses having a second carrier frequency a second repetition rate to excite selected spins of the spins excited by the first sequence of RF pulses, the second repetition rate being greater than the first repetition rate and the second carrier frequency being within the principal lobe of the frequency spectrum of the first sequence of RF pulses; means for receiving from the spins excited by the first and second sequences of RF pulses, in the intervals between the pulses of the second sequence of RF pulses, resonance frequencies in the form of an interferogram; means for storing the amplitude values of at least one interferogram; and means for computing by Fourier analysis the resonance frequencies comprising the interferogram.
Claim 27
Dependent Claim
173 words
Apparatus for recording spin resonance spectra comprising: means for directing at a sample of at least one type of nuclei a first sequence of RF pulses having a first carrier frequency and a first repetition rate to excite spins of one type of nuclei; means for directing at the sample a second sequence of RF pulses having a second carrier frequency a second repetition rate to excite selected spins of the spins excited by the first sequence of RF pulses, the second repetition rate being greater than the first repetition rate and the second carrier frequency being within the principal lobe of the frequency spectrum of the first sequence of RF pulses; means for receiving from the spins excited by the first and second sequences of RF pulses, in the intervals between the pulses of the second sequence of RF pulses, resonance frequencies in the form of an interferogram; means for storing the amplitude values of at least one interferogram; and means for computing by Fourier analysis the resonance frequencies comprising the interferogram.
Claim 28
Dependent Claim
68 words
The apparatus of claim 24 wherein: the second sequence of RF pulses is formed by an RF generatoR and a pulse-controlled RF gate; the pulse-controlled RF gate is connected to the output of a pulse generator; and the pulse generator is controlled by a variable frequency oscillator, whereby the pulse repetition rate of the generator, and consequently the pulse repetition rate of the RF pulses, may be varied.
References Cited (Backward Citations)
US3530374A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |