NASA satellites measure vector magnetic fields around planets to learn about the geology of the planets. Existing fluxgate magnetometers drift as a result of temperature and aging. A magnetometer whose calibration was stable would improve investigations of planets and the solar system.
This vector magnetometer is based on NMOR (nonlinear magneto-optical rotation) and modulation of total magnetic field. The NMOR technology measures magnetic fields by determining the Larmor frequency from optical rotation of a probe beam by an atomic vapor. The optical rotation results from an optically pumped coherence. A unique feature of NMOR is that the sensitivity depends on the quality of a coating that controls the lifetime of the coherence. Improvements in coating technology should result in higher sensitivity. A second advantage of NMOR technology is that it is based on an alignment coherence, which minimizes systematic errors. Coils are used to apply additional magnetic fields, similar to the self-calibrated He vector-scalar magnetometer.
This work was done by Chris Hovde of Southwest Sciences, Inc. for Goddard Space Flight Center. For further information, contact the Goddard Innovative Partnerships Office at (301) 286-5810. GSC-16015-1
