Effective Area Measurements of Magnetic Pick-Up Coil Sensors for RFX-mod2.

A meaningful characterization of the magnetic configuration of toroidal plasmas requires the identification and estimation of the sources of error on each magnetic measurement of the overall diagnostic system. Thus, the correct characterization of magnetic pick-up coil sensors and the assessment of their reliability becomes a necessary requirement before their permanent installation in the RFX-mod2 experiment. The experimental characterization methodology developed for the three-axes magnetic pick-up coil sensors of RFX-mod2 experiment is presented here. The sensitivity of each sensor is evaluated not only by performing accurate measurements of the effective areas in a time-varying magnetic field, but also by checking the alignment of the magnetic axes through measurements of the effective areas at different rotation angles. Moreover, the effect of thermal cycles on measuring the effective area and the angle of misalignment are evaluated and analyzed.