Conversion of a Varian 40 Mc/s high resolution nuclear magnetic resonance spectrometer to 80 Mc/s operation
S A Knight; R L Erskine; S A Knight; The British Petroleum Co. Ltd., Sunbury-on-Thames, Middlesex; R L Erskine; The British Petroleum Co. Ltd., Sunbury-on-Thames, Middlesex
Журнал:
Journal of Scientific Instruments
Дата:
1965-09-01
Аннотация:
The conversion of a 40 Mc/s Varian nuclear magnetic resonance spectrometer to 80 Mc/s operation is described. The increase in maximum field strength from 12 to 22.5 kG was achieved by the use of conical Permendur pole caps. The factors affecting pole-cap geometry are discussed. Sufficient field homogeneity for the production of high resolution 80 Mc/s hydrogen nuclear magnetic resonance spectra was achieved with Golay electric shim coils. Further stability of the magnetic field, enabling spectra to be recorded on precalibrated chart paper, was achieved by a double audio-frequency modulation technique. Notes are also given on the associated changes required to the electronic circuits.
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