HOLE-BURNING IN A WELL-CHARACTERIZED NOISE FIELD - NONADHERENCE TO THE BLOCH EQUATIONS

Applicability of the Bloch equations for describing relaxation in the saturation regime is studied experimentally and theoretically. Hole bu rning in the proton NMR line of water was observed, and the shape and width of the hole were investigated in a well-characterized noise fiel d. The behavior of power broadening is remarkably different from that expected from the Bloch equations and strongly depends on the correlat ion time of the noise field. The hole shape is not a single Lorentzian . The experimental results are well explained by a stochastic theory o f power broadening. We show that the hole burning in well-characterize d noise fields is very useful for the experimental test of power-broad ening theories.