Sonda con bajo tiempo muerto para relaxometría por resonancia magnética nuclear

Abstract

A probe for nuclear magnetic resonance relaxometry, designed with the main objective of achieving a short dead time, is presented. Its configuration includes independent circuits for transmission and reception, a high-speed switch, a damping resistor and a low noise figure preamplifier. The dead time reduction is reached through the combination of detuning, transient damping and control of the acting times of the switch. The probe allows starting the acquisition of the signal about 5ms after the end of the excitation pulse. This result minimizes the loss of the initial part of the free induction decay and extends the application of the probe to the analysis of substances with short relaxation times. The proposed design and some signals acquired with the device are shown in this work.