Abstract
A nuclear induction spectrometer for the measurement of short relaxation times and the study of saturation and related phenomena is described. Radio-frequency intensities of up to 10 gauss are attainable from four to ten megacycles. Novel features of the apparatus are an rf head for use in a liquid helium cryostat, transmitter output level stabilization circuit, and a calibration circuit for comparing the intensity of the absorption at different rf levels.