Electricity: measuring and testing – Particle precession resonance – Using a nuclear resonance spectrometer system
Patent
1995-07-19
1996-12-03
Tokar, Michael
Electricity: measuring and testing
Particle precession resonance
Using a nuclear resonance spectrometer system
324307, G01V 300
Patent
active
055811825
ABSTRACT:
Methods and apparatus for broadband decoupling in nuclear magnetic resonance with chirp and other RF pulses are disclosed. Such methods may include the step of positioning the sample in a static magnetic field. Additional steps may define a first cycle of pulses, such as chirp pulses, wherein at least two of the pulses have a different initial phase angle from each other and may define a second cycle of pulses wherein at least two of the pulses in the second cycle have an initial phase angle different from the initial phase angles of the pulses in the first cycle. Further steps may repeatedly generate a supercycle of the first and second cycles to produce pulses for inverting the longitudinal magnetization in the sample and may also detect the signals emitted by the sample in response to inversion of the longitudinal magnetization. Alternatively, the chirp pulses in the first and second cycles may be defined to sweep a bandwidth of 100 kHz or more. The first and second cycles may also be defined to include linear frequency modulated RF pulses wherein each of the RF pulses has an amplitude which is substantially constant during at least about 50% of the pulses. Apparatus for performing the disclosed methods is also disclosed. Other methods and apparatus are also disclosed.
REFERENCES:
patent: 4443761 (1984-04-01), Levitt
patent: 4470014 (1984-09-01), Levitt et al.
patent: 4682106 (1987-07-01), Vatis et al.
patent: 4959612 (1990-09-01), Luyten
patent: 5073752 (1991-12-01), DeMeester et al.
patent: 5126671 (1992-06-01), Bodenhausen et al.
patent: 5327086 (1994-07-01), Bodenhausen et al.
patent: 5384573 (1995-01-01), Turpin
R. Tycko et al., "Iterative Schemes for Broad-Band and Narrow-Band Population Inversion," Chemical Physics Letters, vol. 111, No. 4,5, pp. 462-467 (1984).
A. J. Shaka et al., "Broadband Spin Decoupling in Isotropic Liquids," Progress in NMR Spectroscopy, vol. 19, pp. 47-129 (1987).
Toshimichi Fujiwara et al., "Composite Inversion Pulses with Frequency Switching and Their Application to Broadband Decoupling," Journal of Magnetic Resonance 77, pp. 53-63 (1988).
T. Fujiwara et al., "Communications: Frequency-Switched Composite Pulses for Decoupling Carbon-13 Spins Over Ultrabroad Bandwidths," Journal of Magnetic Resonance, Series A 104, pp. 103-105 (1993).
Zenon Starcuk, Jr., et al., "Heteronuclear Broadband Spin-Flip Decoupling with Adiabatic Pulses," Journal of Magnetic Resonance, Series A 107, pp. 24-31 (1994).
M. Robin Bendall, "Broadband and Narrowband Spin Decoupling Using Adiabatic Spin Flips," Journal of Magnetic Resonance Series A 112, pp. 126-129 (1995).
M. S. Silver et al., "Selective Population Inversion in NMR," Nature vol. 310, pp. 681-683 (1984).
M. S. Silver et al., "Highly Selective .pi./2 and .pi. Pulse Generation," Journal of Magnetic Resonance 59, pp. 347-351 (1984).
M. S. Silver et al., "Selective Spin Inversion in Nuclear Magnetic Resonance and Coherent Optics Through an Exact Solution of the Bloch-Riccati Equation," Physical Review A, vol. 31, No. 4, pp. 2753-2755 (1985).
J. Bohlen et al., "Experimental Aspects of Chirp NMR Spectroscopy," Journal of Magnetic Resonance, Series A 102, pp. 293-301 (1993).
M. A. McCoy et al., "Selective Shaped Pulse Decoupling in NMR: Homonuclear [.sup.13 C] Carbonyl Decoupling," J. Am. Chem. Soc., 114, pp. 2108-2112 (1992).
R. R. Ernst, "Nuclear Magnetic Double Resonance with an Incoherent Radio-Frequency Field," The Journal of Chemical Physics, vol. 45, No. 10, pp. 3845-3861 (1966).
V. J. Basus et al., "Utilization of Chirp Frequency Modulation with 180.degree.-Phase Modulation for Heteronuclear Spin Decoupling," Journal of Magnetic Resonance 35, pp. 19-37 (1979).
M. H. Levitt et al., "Composite Pulse Coupling," Journal of Magnetic Resonance 43, pp. 502-507 (1981).
A. J. Shaka et al., "Evaluation of a New Broadband Decoupling Sequence: WALTZ-16," Journal of Magnetic Resonance 53, pp. 313-340 (1983).
A. J. Shaka et al., "Computer-Optimized Decoupling Scheme for Wideband Applications and Low-Level Operation," Journal of Magnetic Resonance 64, pp. 547-552 (1985).
J. S. Waugh, "Theory of Broadband Spin Decoupling," Journal of Magnetic Resonance 50, pp. 30-49 (1982).
M. A. McCoy et al., "Selective Decoupling," Journal of Magnetic Resonance, Series A 101, pp. 122-130 (1993).
U. Eggenberger et al., "Frequency-Selective Decoupling with Recursively Expanded Soft Pulses in Multinuclear NMR," Journal of Magnetic Resonance 100, pp. 604-610 (1992).
M. Levitt et al., "Supercycles for Broadband Heteronuclear Decoupling," Journal of Magnetic Resonance 50, pp. 157-160 (1982).
Bodenhausen Geoffrey
Fu Riqiang
Florida State University
Tokar Michael
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