Experimental Research of Reconnection Heating / Acceleration by Ion Flow and Temperature Profile Measurement Probe Array

We developed a 1D spatial profile measurement of ion flow and temperature by a parallel glass-tube-pair type Doppler spectroscopy probe array. This diagnostic can measure ion flow and temperature at 7 points on a straight line at 2.5 cm intervals by a single shot. Using the system, we measured the time evolution of the radial profile of ion flow and temperature around the diffusion region of two merging tokamak plasmas. We found that the maximum heating point where the local temperature increment ≃ 40 eV agrees with the point where the outflow(the maximum local outflow speed ≃ 8 km/s) damps to < 1 km/s. We observed for the first time that the direction of ion outflow rotated 90 degrees to that of the quadrupole poloidal electric field by the Hall effect after the completion of guide field reconnection. We are measuring the spatial profile of ion density and poloidal field to examine the Rankine-Hugoniot relations for fast shock. We are now upgrading 1D spatial profile measurement to 2D spatial profile measurement by increasing the number of parallel glass tube pairs for the purpose of validating the ion acceleration by the quadrupole poloidal electric field.