A Room-Temperature Operational Alignment Magnetometer Utilizing Free-Spin Precession

An alignment magnetometer based on free-spin precession (FSP) has been deployed in the geomagnetic range. A linearly polarized probe beam is utilized to create alignment in a buffer-gas-free paraffin-coated natural abundance rubidium vapor cell at room temperature exposed to a pulsed radio frequency field. Furthermore, the utilization of hyperfine-selective optical repumping employing linearly polarized beams amplifies the proportion of responsive atoms. As a consequence, this leads to a remarkable enhancement in the optical rotation signal. This paper reports measurements with a minor static magnetic field of about 1 (Formula presented.) inside a four-layer (Formula presented.) -metal shield, achieving a system noise level of 0.16 (Formula presented.)) (Formula presented.). With a static magnetic field amplitude of 48.5 (Formula presented.) (in proximity to Earth's magnetic field), the noise level is (Formula presented.) (Formula presented.)) (Formula presented.).