투고논문

Magnetic Field Standards Using Magnetic Resonance

Po Gyu Park*, Wan-Seop Kim, Sung Jung Joo and Hyung Kew Lee

Center for Electricity and Magnetism, Korea Research Institute of Standards and Science, Daejeon 34113, South Korea

 Abstract The nuclear magnetic resonance (NMR) and atomic magnetic resonance (AMR) plays a fundamental role in achieving a high accuracy of magnetic field measurements. Magnetic field unit (T) was realized based on the shielded proton gyromagnetic ratio (g'_P), helium-4 gyromagnetic ratio (g_4He) and related techniques. The magnetic field standard system has been disseminated by the NMR magnetometer and electromagnet, a Helmholtz coil system, and AMR magnetometer in the nonmagnetic laboratory. A magnetic field standard below 1 mT has been developed by using Cs and Cs- ⁴He AMR with automatic compensation of an external magnetic field noise. The standards serve for the calibration of magnetometers and support the test of sensors and materials in the range from 5 μT to 2.0 T with (1 to 50) μT/T uncertainty (k=2).