Measuring the relaxation time of the xenon atoms and the rubidium atoms

摘要

In a nuclear-magnetic-resonance gyroscope (NMRG), the polarization of nuclear spins and the detection of motional information are usually achieved by utilizing the atomic spins of alkali atoms. The parameters of the atomic spins are mainly evaluated by the relaxation time. Relaxation time is very important and can influence signal-to-noise ratio, dynamic range, start time, and other gyroscope parameters. Therefore, its accurate measurement is critical in the study of NMRG performance. In this study, we evaluate a variety of methods to measure the transverse and longitudinal relaxation times. First we examine the free-induction-decay method, which is the industry standard for measuring spin relaxation time. Second we investigate the improved free-induction-decay, fitting-ratio, and magnetic-resonance-broadening-fitting methods for measuring the transverse relaxation time, and the flipped polarization method for measuring the longitudinal relaxation time. By changing the experimental conditions, we obtain the longitudinal relaxation time using the flipped polarization method under a variety of conditions. Finally, by comparing these measurement methods, we propose the best measurement methods under different conditions.