Ion and Electron Heating Characteristics of Magnetic Reconnection in TS-3 and UTST Merging Startup Experiments

The high-power heating of magnetic reconnection has been applied to the ultra-high-beta ST formation in the TS-3, TS-4 and UTST merging experiments. Two low-beta ST plasmas were formed inductively by two or four PF coils without using any central solenoid (CS) and were merged for high power MW-GW reconnection heating. Cause and mechanism for the reconnection heating were directly measured for the first time by two dimentional ion and electron temperature measurements. While electrons were quickly heated inside current sheet by its ohmic heating power, ions were heated in the downstream area by shock or viscosity damping of the reconnection outflow. The magnetic reconnection transformed the magnetic energy of reconnecting magnetic field to the ion thermal energy, increasing the plasma beta of ST up to 0.5.