Sawtooth heat pulse propagation and electron heat conductivity in HL-1

The propagation of heat pulse induced by sawteeth was studied in hydrogen and helium plasma for a wide range of plasma parameters. The propagation time of heat pulse is quadratic in the radius. The electron heat conductivity χe(r) in the outer confinement region of the plasma was deduced from the propagation time of the heat pulse on the high and low field sides of the plasma column. It is concluded that the value of χe(r) outside the mixing radius is related to the sawtooth inversion radius, the electron density and the sawtooth period. A comparison of χe determined by heat pulse propagation with those obtained from power balance have been made. (author) 3 refs., 6 figs