In-situ measurement of cell temperature by spin-relaxation rate analysis for an atomic magnetometer

Alkali-metal vapor cells are the core sensing components of atomic magnetometers. To achieve high-sensitivity magnetic field measurements, the cells require heating and stabilization at high temperatures. Here, we propose an in-situ temperature measurement method for a vapor cell of an atomic magnetometer based on spin-relaxation analysis. This technique establishes a direct functional correlation between the cell temperature and the spin-relaxation rate under low pumping power conditions. Experimental validation within the temperature range of 90 °C–130 °C confirms the accuracy of this approach. We further investigate the effects of magnetic fields on measurement precision and demonstrate the long-term, high-precision capabilities of temperature detection. This non-invasive technique presents a critical advantage for precise thermal optimization of atomic magnetometers.