Surface protection from high energy electrons and X-ray radiation analysis in tokamak plasma.

Abstract

Plasma cooling due to hard x-ray radiation from the Runaway electrons is an important issue in tokamaks. Thus, developing effective methods to reduce the Runaway electrons and the emitted hard x-ray is also important for optimal tokamak plasma operation. In this study, we investigated the effects of external fields on hard x-ray intensity and the Magnetohydrodynamic (MHD) activity. In other words, we presented the effects of positive biased limiter and Resonant Helical Field (RHF) on the MHD fluctuations and hard x-ray emission from the Runaway electrons. MHD activity and hard x-ray intensity were analyzed using Wavelet transform in the presence of external fields and without them. The experimental results showed that the MHD activity and therefore the hard x-ray intensity could be controlled by the external electric and magnetic fields.