Measurement of Rabi oscillation in a spin system

Abstract

This work proposes that during the application of an on-resonance MR- pulse there exists a Rabi oscillating fi eld which can be directly measured from a nuclear spin system. These oscillations have been previously inferred through a series of varied pulsed-length free induction decay (FID) mea- surements, however direct observation of a continuous oscillation has not previously been reported. Due to the existence of this oscillation only dur- ing application of an radio-frequency (RF) eld, it's detection is complicated by the strength of the applied RF which is orders of magnitude greater than Rabi signal. In order to mitigate the overpowering signal from the applied RF eld, several signal conditioning stages were required for detection of these oscillations. The dependancy of the detected Rabi oscillation frequency with respect to strength of the applied RF field, and sample size were validated. Furthermore, the eld strength due the observed Rabi oscillations was de- termined and compared to theoretical simulations to within experimental accuracy.