Lifetime estimation model of vapor cells in atomic magnetometers

Abstract

A lifetime estimation model is proposed by characterizing the consumption of the components inside the atomic vapor cells in this work. The buffer gas leakage and alkali metal consumption in vapor cells will significantly destroy the performance of atomic magnetometers. Combining the light absorption method and aging experiments, the deterioration of helium pressure, rubidium vapor density, and cell wall transmittance were obtained to construct the lifetime estimation model that depends on time, working temperature, and initial contents. Then, the causes and consequences of these deteriorations were analyzed, and the combination of theoretical analysis and experimental data showed that the vapor cell invalidation caused by these factors conforms to the Weibull distribution. In order to establish the relationship between the component consumption and the performance of the magnetometer constituted by this cell, a single-beam magnetometer prototype was designed for sensitivity testing. Experiments have shown that the sensitivity of magnetometer is rapidly deteriorating after operating 600 hours under 150 ℃, which is mainly related to alkali metal consumption. Additionally, 200 ℃ is a trade-off aging experimental temperature between the aging efficiency and the stability of the cell. The proposed model can be applied to optimize the lifetime of the vapor cells used not only in magnetometers but also in gyroscopes and atomic clocks.

A robust method for performance evaluation of the vapor cell for magnetometry

“…[10,11] Artificial operations during the fabrication process affect the components of the vapor cells, resulting in inconsistent parameters in the same batch. [12,13] The vapor cell and other components that make up a miniaturized magnetometer are rigidly connected and cannot be disassembled without damage. Therefore, it is necessary to evaluate the performance of the vapor cell before assembling the magnetometer.…”