SYSTEMATIC SOURCES OF SIGNAL IRREPRODUCIBILITY AND T(1) NOISE IN HIGH-FIELD NMR SPECTROMETERS

Many of the most powerful modern NMR techniques rely heavily on spectrometer stability and reproducibility. Any deficiencies in these two parameters result in such artifacts as t1 noise in 2D NMR and spurious signals in difference spectra. One of the most important sources of error in NMR signals is the irreproducibility of the effective phases of radio-frequency pulses. In this paper a successful search for systematic sources of such errors in a modern spectrometer is described, and suggestions are given for their treatment. In the spectrometer under study, a threefold improvement in pulse reproducibility was achieved. © 1992.