Illustrated Glossary of Organic Chemistry

B₀: In NMR spectroscopy, the magnetic field experienced by the nucleus. Its magnitude is due to the Earth's magnetic field, the magnetic field applied by the NMR spectrometer, the magnetic field created by electrons orbiting the nucleus, plus the magnetic fields of adjacent atoms.

This 600 MHz NMR spectrometer uses a superconducting magnet (the white cylinder to the left) that is cooled to 4 K with liquid helium.