Effects of temperature on Rb and 129Xe spin polarization in a nuclear magnetic resonance gyroscope with low pump power

Abstract

We propose an average Rb polarization model to analyze the influence of temperature on the spin polarization of Rb and 129Xe in a Nuclear Magnetic Resonance Gyroscope (NMRG) with low pump power. This model is essentially based on summing the Rb spin polarization along the direction of the pump beam and dividing the result by the cell length. We experimentally study the spin polarization of Rb and 129Xe atoms as a function of the cell temperature at low values of the pump power. The experimental results and the values calculated with the average Rb polarization model are in good agreement for both Rb and 129Xe. The spin polarization of Rb atoms decreases with increasing cell temperature, with a decreasing trend which is rapid at temperatures below 110 °C, and slower at temperatures above 110 °C. The experimental values of the 129Xe polarization, obtained with a pump power of 1 mW, first increase to a maximum P 129Xe−ave = 0.66 % at 118 °C, and then decreases as the temperature increases. Increasing the power of the pump beam shifts the temperature maximum to a higher value. Our model is suitable for the analysis of Rb and 129Xe polarization at high temperature and low pump power, i.e. when the power of the pump beam is completely absorbed within a few millimeters of the front window of the cell. Therefore, the present model can provide theoretical support for the improvement of the Signal-to-Noise-Ratio (SNR) of the NMRG, and to determine its optimal working temperature.

Investigation of spatial spin polarization of 87Rb and 129Xe atomic ensemble pumped by Gaussian beam in a miniature nuclear magnetic resonance gyroscope

“…In conclusion, the coupled spin polarization modelling process for Rb and Xe atoms ensemble of a nuclear magnetic resonance gyroscope is presented in detail. Based on the model, the three dimensional distribution of the spin polarization field of Rb and Xe atoms is obtained by numerical solution and the results are in good agreement with the experiment results obtained by L. Chen et al [5]. Influencing factors including temperature, power and detuned frequency of the pumping laser, anti-relaxation coatings and partial pressure of gas composition are investigated.…”

“…2 shows the 87 Rb electron spin polarization averaged over the cell varying with the cell temperature through simulation. In order to verify the polarization model and the numerical solution, reference is made to the experiment data of L. Chen et al 5 . These data are from the Fig.…”

“…As a result, it is necessary to establish a comprehensive method for analysis of spin polarization influence that involves multiple factors. L. Chen et al proposed an average Rb polarization model to analyze the influence of temperature on the spin polarization of Rb and 129 Xe in a Nuclear Magnetic Resonance Gyroscope (NMRG) with low pumping power 5 . However, since they did not consider spin diffusion of the spin polarization, anti-relaxation coatings on the inner surface of the gas cell, pumping beam inhomogeneity, accuracy of the model needs to be further improved.…”

Design of a multi-laser module for optical pumping in compact atomic gyroscopes

“…[20][21][22] However, when there are noble gas atoms which require to be hyper-polarized, many research indicated that 1 mW pump power is generally not sufficient. [23][24][25][26] This causes great challenges to the development of compact atomic gyroscopes.…”

General analytical method of designing shielded coils for arbitrary axial magnetic field*

“…With the rapid development of quantum technology, specific magnetic field coils are increasingly required in many applications, [1] such as atomic clock, [2,3] optical pumped magnetometer, [4][5][6][7][8] nuclear magnetic resonance gyro, [9,10] and magnetic trap. [11][12][13][14][15] Although many kinds of magnetic coils [14][15][16][17][18][19][20][21][22][23] have been invented for these applications respectively, there is still a lack of a common method to design these coils conveniently, or even to realize any required magnetic field systematically.…”