Calculation of pulsed NMR signal in I=3/2 quadrupolar spin system

The rf pulse response of I = 3/2 spin system experiencing;first order quadr upolar splitting is studied using density matrix approach. A general expres sion is derived in terms of spin populations, quadrupole splitting and dura tion and amplitude of the rf pulse for calculating the NMR signal arising d ue to the centre Line and satellite resonances for the situation where the impressed rf pulse excites the resonances selectively as well as non-select ively. The necessary 4 x 4 transformation matrix obtained analytically by d iagonalyzing the Hamiltonian are used to get the expression for the centre line response. The satellite signals are obtained in the same way but by us ing the numerical values of the roots of the related quartics, The widths o f the corresponding pi/2-pulses are calculated for different initial spin p opulations, The variations of this pulse-width and the corresponding signal amplitude as a function of satellite splitting are studied. (C) 2000 Elsev ier Science B.V. All rights reserved.