Techniques of Ultrasonic Paramagnetic Resonance

Ultrasonic paramagnetic resonance (UPR) techniques are given for recording the derivative of UPR absorption with respect to magnetic field and for measurement of spin relaxation rates. The X‐band pulse echo, spin relaxation spectrometer utilizes high power pulses from one magnetron to saturate the spin system. Low power pulses from another magnetron are then used to monitor the recovery from saturation by varying the delay between the saturating and monitoring pulses.