Optimization of the metallic vessel-wall effect on the magnetic diagnostics calibration in ADITYA-U tokamak

摘要

ADITYA-U has been recently upgraded to limiter-divertor configuration from limiter configuration. Commissioning of various magnetic diagnostics along with the data acquisition system is done to measure the plasma parameters. Measurement of various plasma parameters will be used to control the real-time plasma position, shape and post-discharge fluctuation measurement and equilibrium reconstruction. Magnetic probe measurement is the appropriate diagnostic technique as they are easy to install and calibration can be done in the absence of the plasma. A different set of magnetic probes are installed inside and outside the vacuum vessel of ADITYA-U to pick up the magnetic signals of the plasma. In-Situ calibration of the magnetic probe is performed in ADITYAU to mitigate the effects generated due to geometrical imperfection of the probes and deviation in the probe mounting, which are the main source of error. During the calibration experiment in ADITYA-U, the effect of induced vessel current due to the time-varying magnetic field of the central conductor has been observed and examined in detail for different experimental cases. Optimization of the effects generated due to vessel current on the magnetic diagnostic is presented in this paper.