Means of Reducing Ringing Times in Pulsed Nuclear Magnetic Resonance

Two auxiliary circuits are described for incorporation in a pulsed nuclear magnetic resonance system to reduce the deadtime of the system following an rf exciting pulse. The function of one, a driven balanced clamp, is to reduce the Q of the detecting circuit for a controlled time after each pulse. The other, a symmetric damping circuit requiring little operating power, works in conjunction with the transmitter to ``square‐up'' the rf pulses generated. The circuits presented here represent certain improvements in established techniques of clamping and damping. Additionally, it is pointed out that there is a particular advantage, with respect to minimizing the deadtime in a coherent system, of using timing pulses which are phase locked to the rf reference.