AbstractThe clouds surrounding deuterium and hydrogen pellets with 0.3–1.4 mm sizes and 500–700 m s−1 velocities injected in the plasma core direction were studied experimentally. The cloud temperature profiles Tcl(z) along the magnetic field direction were measured by means of the ratio of the line intensity I1 to the continuum intensity Ic for different minor radii. It was observed that Tcl(z) profiles have a region with constant values of Tcl ≈ 2–3 eV owing to the constant values of I1, Ic intensities. The toroidal size of this region varied with the pellet ablation rate. Far away from this region the cloud temperature increased with maximal absolute values of the space gradient dTcldz = 0.30.6 eV cm−1. The spatial gradient and the temperature in the centre of the profiles Tcl(z) exhibit a weak dependence on the pellet ablation rate values.