| abstract |
Apparatus for detecting nuclear magnetic resonance in which the sample is subjected to a high magnetic field in one direction to polarize the nuclear spins, then an alternating radio frequency magnetic field is applied to the sample and varied from a frequency below the resonant frequency of interest of the sample to a frequency above the resonant frequency, or vice versa, at a rate which provides adiabatic fast passage. A detector detects the change in the magnetization parallel to the direction of the magnetic field during said adiabatic fast passage. The method of detecting nuclear magnetic resonance which comprises polarizing the sample, changing the steady state value of the longitudinal magnetization and detecting the change in the steady state value of the longitudinal magnetization. |