Observation of the London moment and trapped flux in precision gyroscopes

The London-moment readout has been observed in flight quality gyroscopes and it has been demonstrated that it is possible to reduce magnetic field trapped in these gyroscopes to levels as low as 1.5 x 10 exp -11 T. A preliminary analysis shows that the horizontal component of the London-moment signal is 60 percent of the total expected London-moment signal and is proportional to the gyro spin speed. Experiments were carried out in a unique ground test facility which was designed to provide the conditions necessary to observe the London moment of the spinning gyroscope.