Title :
Direct measurements of the magnetic field induced by optically polarized 3He atoms
Author :
Gudoshnikov, S.A. ; Kozlov, A.N. ; Maslennikov, Yu.V. ; Serebrjakov, A. Yu ; Snigirev, O.V.
Author_Institution :
Dept. of Phys., Moscow State Univ., USSR
fDate :
3/1/1991 12:00:00 AM
Abstract :
An alternative magnetic field induced by the standard cell of an optically pumped 3He magnetometer has been directly measured by the SQUID-based second-order gradiometer with a signal-to-noise ratio higher than six. A measured field of 5×10-13 T at a 5-cm distance from the cell axis and a transverse relaxation time of 7 min have been found. The measured transverse decay time was equal to 7 min; thus, the resolution in the frequency domain is limited at a level on the order of 10-3 Hz, which corresponds to an uncertainty of approximately 5×10-11 T. The results imply that the direct measurement of the induced field in the optically pumped 3 He magnetometers makes it possible to introduce a suitable metrological scale in the region of the weak magnetic field 5×10 -8 T<B0<5×10-5 T
Keywords :
SQUIDs; helium neutral atoms; magnetic field measurement; magnetometers; measurement standards; 5×10-8 to 5×10-5 T; SNR; direct measurement; magnetic field; metrological scale; optically polarized 3He atoms; optically pumped 3He magnetometer; second-order gradiometer; standard cell; transverse decay time; Frequency domain analysis; Frequency measurement; Helium; Magnetic field measurement; Measurement standards; Optical pumping; SQUID magnetometers; Signal resolution; Signal to noise ratio; Time measurement;
Journal_Title :
Magnetics, IEEE Transactions on
