ABSTRACT
This chapter is the first devoted to N.M.R. and more specifically to continuum waves (C.W.) N.M.R. It concerns essentially liquid systems or solutions. High-resolution NMR applies to these samples. First, the theory is widely developed. NMR depends on the existence of a nuclear spin. Besides, the chapter mentions the characteristics of some active nuclei. In an NMR experiment, the nuclei of the element to study are submitted to a magnetic field and, jointly, to electromagnetic radiation which produces a change in their energy levels. The absorbed or emitted energies obey Bohr’s condition. The transitions are located in the domain of radio frequencies. Phenomena of relaxation, which are the cause for which the intensities of the signals in NMR do not reach a saturation state, are also discussed. An apparatus is briefly described. The form of the peaks together with the widths of the rays and their intensity are investigated.
