A double pulse method of N.Q.R. detection

Abstract

A method of n.q.r. detection is described in which pairs of radiofrequency pulses from a super-regenerative oscillator excite and detect resonance. For large enough intervals of time between successive pairs of pulses, the nuclear signal produced by any pair decays well below noise level at the arrival of the next pair, so that the first pulse of each pair does not detect n.q.r. The second pulse is then moved along the nuclear induction signal, produced by the first pulse of each pair, to record its variation as a function of time. A method is given for the evaluation of the apparent spin-spin relaxation time from measurements taken using a sample of p-dichlorobenzene at 23°C.