Graphic method of calculating echo-response parameters under conditions of multipulse excitation of quantum systems

Multipulse excitation of systems is widely used in nonlinear spectroscopy. In high-resolution NMR spectroscopy of solids excitation by a succession of many pulses makes it possible to substantially suppress resonance line broadening. Such sequences are used in echo-spectroscopy, making it possible to obtain a more informative or the same response as with a signal of a two-pulse echo. Therefore it is important to predict theoretically the action of multipulse system excitation. This article presents an approach for obtaining faster and more complete information on the generating signals. Comparing the responses with graphically determined elements, by the shape of the latter the author finds formation times, wave vectors, and complex amplitudes of signals; he determines their dependence on reversible T/sub 2/ and irreversible T/sub 1/, T/sub 2/ phase relaxation times, as well as on spectral diffusion processes. By means of the given method the author succeeded in finding pulse sequences leading to response generation with new dependences on cross sections of the exciting pulses.