Recent Development of Magnetic Field Measurements on Rotamak

The new development of magnetic field measurements includes a series of Mirnov array for the study of magnetohydrodynamic (MHD) instability, and a magnetic probe array for the measurement of internal 3-Dimension magnetic field. The system of Mirnov array consists of four sets magnetic pick-up coils located at $Z=\pm $ 4 cm and $Z=\pm $ 30 cm along chamber axis; each array is made up of eight $B_{R}$-oriented coils mounted around the chamber surface at an equal interval of 45$^{\circ}$ toroidal angle. The 3-Dimentinal probe array was originally made at RPPL with University of Washington, Seattle; the probe array has a total of 90 windings that can be used to simultaneously measure $B_{r}, B_{\theta}$, and $B_{z}$ at 30 radial positions. The detailed system design which includes the data acquisition system and the primary experimental results will be presented.