Gas magnetometer

摘要

Measurement of a precessional rate of a gas, such as an alkali gas, in a magnetic field is made by promoting a non-uniform precession of the gas in which substantially no net magnetic field affects the gas during a majority of the precession cycle. This allows sensitive gases that would be subject to spin-exchange collision de-phasing to be effectively used for extremely sensitive measurements in the presence of an environmental magnetic field such as the Earth's magnetic field.

主权项

1. A magnetometer comprising:
a chamber holding a gas exposable to an external magnetic field other than that generated locally by the magnetometer and directed along a z-axis; an electromagnet positioned to apply a local magnetic field to the chamber; a signal source communicating with the electromagnet and generating a field signal adapted to drive the electromagnet to produce a local magnetic field causing a non-uniform precession of a magnetic moment of the gas limiting a portion of each cycle of the field signal during which substantial precession occurs; and a detector measuring a frequency of the non-uniform precession of the magnetic moment to provide an output indicating a strength of the external magnetic field.