TRANSPORT STUDIES IN THE TJ-I TOKAMAK FROM STEADY AND PERTURBATIVE METHODS

Transport analysis in the steady state and the natural perturbation of the sawteeth observed in electron temperature and density measurement s in ohmic discharges of the TJ-I tokamak are used for studying the de pendence of particle and electron energy fluxes on density and tempera ture gradients. The results of coupled analysis for propagation of den sity and temperature perturbations give a transport coefficient matrix with negligible off-diagonal terms. The effective electron heat condu ctivity chi is one order of magnitude greater than the effective parti cle diffusion coefficient D. The heat conductivity obtained from heat pulse measurements is close to that obtained from power balance analys is. The diffusion coefficient from density pulses is also close to tha t obtained from steady state analysis assuming a neoclassical inward p inch. A strong relationship of the deduced heat conductivity with q pr ofile was found, which can be interpreted as due to tearing modes. A u nified expression for particle and energy fluxes, which explains the r esults of pulse propagation and steady state profiles, is also given.