Evidence for small scale magnetic structures in the RTP tokamak

Abstract
High resolution Thomson scattering measurements of electron temperature and density in RTP show several hot filaments in the plasma centre and sharp gradients near the sawtooth inversion radius under central ECH, and structures outside the sawtooth region both in ohmic and ECH plasmas. These measurements give evidence of a complex magnetic topology. A numerical scheme is proposed which allows computation of the magnetic equilibrium with broken surfaces. Some properties of transport in a inhomogeneous medium are discussed.