Ultra-sensitive atomic magnetometer system for airborne magnetic anomaly detection

Tristan Technologies, in collaboration with Prof. Romalis of Princeton University, propose to develop a magnetic anomaly detection (MAD) system based on a unique ultra-sensitive atomic magnetometer technology. Magnetometers developed at Princeton achieved world-record sensitivity of 0.5 fT/,cHz with a measurement volume of 0.3 cc. A primary challenge in airborne MAD is achieving high field sensitivities in a low frequency range (0.04-0.5 Hz) in the environment of large magnetic noise and motion platform vibration. Based on the platform dynamics, optimal magnetometer operation and detection parameters will be chosen, including vector magnetometer in zero field and scalar magnetometers with high spin polarization and modulated pumping light. A synthetic gradiometer will be constructed from two atomic magnetometers and a 3-axis fluxgate, operating in a feedback mode. The goal is to demonstrate real-world operation of the gradiometer system, gradiometer sensitivity, effectiveness of feedback, and dynamic range sufficient for deployment on a motion platform. We will demonstrate 1/f noise reduction through use of two-probe laser operation mode. Phase I will culminate in the conceptual system design for airborne MAD, including sensor array, data acquisition, algorithms for noise cancellation, control of motion/vibration induced noise, ruggedization and packaging suitable for fleet operation.