Magnetic topology near the q = 1 surface derived from the soft X-rays measurements in the TFR 600 Tokamak

The q = 1 magnetic island structure is investigated by soft X-ray technique and interpreted with a numerical model, in order to give some insight about some open questions: q = 1 surface radius, island existence, island size evolution, ... etc ... A conventional silicon detectors array with a central spatial resolution of 1 cm and a bandwidth of 50 kHz measures the soft X-ray flux from 6 cm radius plasma cylinder (The limiter radius is 20 cm). An observed internal relaxation, is synthetized by the numerical model. At a given time a magnetic surface set is assumed; the synthetic signal obtained by integrating the X-ray emissivity along each chord, is then fitted to the experimental fluxes, by adjusting several parameters of the numerical model