Research of long-time stability of an atomic magnetic resonance standard system for reproduction of direct current and magnetic flux density

At the D. I. Mendeleyev Institute for Metrology (VNIIM) a standard system using helium-4 atomic magnetic resonance has operated during the past 10 years for reproduction of low magnetic flux density and direct current. Research of the base elements of this system for the last 5 years have shown that non-stability of the coil-constant of a standard solenoid and nonlinearity of the frequency-to-current conversion coefficient of a quantum system for current reproduction in the range 0.1 A to 1 A are less than 1 /spl times/ 10/sup -7/.