Modifications of the steady-state free-precession sequence for the detection of pure nuclear quadrupole resonance

Abstract

Modifications of the steady-state free-precession (SSFP) sequence are proposed for the effective detection of pure nuclear quadrupole resonance (NQR). These modifications enable the suppression of the effect of intensity anomalies observed under steady-state conditions. The steady-state signals in SSFP-type sequences strongly depend on the frequency offset from resonance and the pulse spacing. This dependence has some peculiarities which were taken into consideration. Experimental results of modified SSFP sequence applications are reported for nitrogen-14 NQR in a plastic explosive.