A  METHOD  FOR  DETERMINATION  OF  NMR  SIGNAL  RESONANCE  FREQUENCIES  AND  DETECTION  OF  THE  EFFECTS  OF  ISOTOPIC  SUBSTITUTION  OF  NUCLEI  IN  HYDROGEN  MOLECULES

Yu. I. Neronov, S. G. Karshenboim

 Saint-Petersburg State University of Information Technology, Mechanics and Optics;
D.I. Mendeleev All-Russia Research Institute of Metrology, Saint-Petersburg


    The paper presents a method for determination of NMR signal frequencies with visual monitoring of optimal separation of radio-frequency signals into real and imaginary parts. The software package developed in this work employs minimization of standard deviations from the calculated profile for both NMK signal components, which provides the statistical error of frequency measurement (delta nu/nu) at the level of about 10^-9 for high magnetic field spectrometers. The method was applied to define chemical shifts at isotopic substitution of hydrogen atoms DELTAsigma = sigma(D2)-sigma(DH) with a search for non-linear effects using magnetic fields В = 7.049 and В = 11.747 Т.