Direct acoustical measurement of nuclear spin-lattice relaxation times: Application to aluminum and tantalum

Abstract

Nuclear spin-lattice relaxation times have been measured using acoustical techniques. These techniques involve the measurement of transient effects in nuclear acoustic resonance. Two methods have been used: progressive saturation, in which the resonance line is repetitively scanned in a time short compared to the relaxation time, and, saturation and recovery, in which the resonance line is first saturated strongly and then observed a variable time later. These methods have been applied to an aluminum alloy, for which the coupling to the nucleus involves the magnetic dipole moment, and tantalum, for which the coupling involves the electric quadrupole moment.