Rapid measurement of longitudinal nuclear spin relaxation time based on the in-situ longitudinal magnetometer in Rb–Xe comagnetometers

Abstract

The longitudinal relaxation time T1 of Xe nuclear spins is an important parameter to determine the performance of Rb–Xe comagnetometers. The industry standard delayed pulse method is time-consuming, and requires multiple π pulses and π/2 pulses. In this work, a direct measurement method for obtaining T1 based on the in-situ longitudinal magnetometer is introduced with the measurement period shortened to 3-5 T1. The proposed method requires only a single π pulse, reducing the measurement time by approximately more than 90%. By solving the Bloch equation, the working principle of the longitudinal magnetometer and the measurement method is demonstrated. The experiment shows that the longitudinal magnetometer achieves a linear working range greater than 60 nT, and the difference in measurement results of T1 through different methods at different temperatures and pump beam power is less than 3%. In addition, the longitudinal magnetometer introduced in this method has broad prospects for measuring the basic physical quantities in comagnetometers.

Keywords

• Rb–Xe comagnetometer
• Longitudinal relaxation time
• Longitudinal magnetometer
• Dynamic response
• Optical pumping spin-exchange