New techniques in nuclear magnetic resonance
<p>The effect of short, strong radiofrequency pulses on the nuclear spin system is examined. Providing the durations of the pulses are short with respect to coupling constants within the spin system, they may be described by simple rotation operators which are exponential functions of the ang...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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1981
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| Subjects: |
| _version_ | 1797079182890500096 |
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| author | Levitt, M Levitt, Malcolm Harris |
| author2 | Freeman, R |
| author_facet | Freeman, R Levitt, M Levitt, Malcolm Harris |
| author_sort | Levitt, M |
| collection | OXFORD |
| description | <p>The effect of short, strong radiofrequency pulses on the nuclear spin system is examined. Providing the durations of the pulses are short with respect to coupling constants within the spin system, they may be described by simple rotation operators which are exponential functions of the angular momentum operators. Operator algebra can be used to define the interaction of such pulses with the spin system, and the mutual interaction of a sequence of pulses. The case of a simple coupled spin system is examined in detail and it is found that a vector model can be used to describe the motion of the expectation values of the observables. This model also allows treatment of such 'non-classical 1 effects as coherence transfer and multiple-quantum coherence. The proposal is also made that certain types of pulse imperfection may be compensated by using specially constructed sequences of small numbers of pulses, which are termed 'composite pulses'. Their compensatory action is illustrated by computer simulation, and by experimental results. In the case of certain symmetrical composite pulses, operator algebra can be used to understand their overall effect in the presence of pulse imperfections, suggesting their use in such critical applications as multiple spin echo trains. Another class of symmetrical composite pulses provides rotations by arbitrary angles around the z-axis of the rotating reference frame, and is expected to be of use in multiple-quantum spectroscopy.</p> |
| first_indexed | 2024-03-07T00:42:06Z |
| format | Thesis |
| id | oxford-uuid:8365b030-de70-4b96-a9a0-e0fd32290551 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T00:42:06Z |
| publishDate | 1981 |
| record_format | dspace |
| spelling | oxford-uuid:8365b030-de70-4b96-a9a0-e0fd322905512022-03-26T21:43:54ZNew techniques in nuclear magnetic resonanceThesishttp://purl.org/coar/resource_type/c_db06uuid:8365b030-de70-4b96-a9a0-e0fd32290551High resolution spectroscopyRadiofrequency spectroscopyNuclear spinNuclear magnetic resonanceEnglishPolonsky Theses Digitisation Project1981Levitt, MLevitt, Malcolm HarrisFreeman, RFreeman, R<p>The effect of short, strong radiofrequency pulses on the nuclear spin system is examined. Providing the durations of the pulses are short with respect to coupling constants within the spin system, they may be described by simple rotation operators which are exponential functions of the angular momentum operators. Operator algebra can be used to define the interaction of such pulses with the spin system, and the mutual interaction of a sequence of pulses. The case of a simple coupled spin system is examined in detail and it is found that a vector model can be used to describe the motion of the expectation values of the observables. This model also allows treatment of such 'non-classical 1 effects as coherence transfer and multiple-quantum coherence. The proposal is also made that certain types of pulse imperfection may be compensated by using specially constructed sequences of small numbers of pulses, which are termed 'composite pulses'. Their compensatory action is illustrated by computer simulation, and by experimental results. In the case of certain symmetrical composite pulses, operator algebra can be used to understand their overall effect in the presence of pulse imperfections, suggesting their use in such critical applications as multiple spin echo trains. Another class of symmetrical composite pulses provides rotations by arbitrary angles around the z-axis of the rotating reference frame, and is expected to be of use in multiple-quantum spectroscopy.</p> |
| spellingShingle | High resolution spectroscopy Radiofrequency spectroscopy Nuclear spin Nuclear magnetic resonance Levitt, M Levitt, Malcolm Harris New techniques in nuclear magnetic resonance |
| title | New techniques in nuclear magnetic resonance |
| title_full | New techniques in nuclear magnetic resonance |
| title_fullStr | New techniques in nuclear magnetic resonance |
| title_full_unstemmed | New techniques in nuclear magnetic resonance |
| title_short | New techniques in nuclear magnetic resonance |
| title_sort | new techniques in nuclear magnetic resonance |
| topic | High resolution spectroscopy Radiofrequency spectroscopy Nuclear spin Nuclear magnetic resonance |
| work_keys_str_mv | AT levittm newtechniquesinnuclearmagneticresonance AT levittmalcolmharris newtechniquesinnuclearmagneticresonance |