Present Progress of Plasma Transport Study on HL-2A

The recent experiments of HL-2A tokamak have been focused on studying the physics of turbulence and transport. A spontaneous particle transport barrier has been observed in Ohmic discharges without any external momentum input. The barrier was evidenced by density perturbation study using modulated supersonic molecular beam injection (SMBI) and microwave reflectometry. The new features of the non-local transport effect induced with SMBI have been analyzed. The suppression of m/n = 2/1 tearing modes may be sustained by ECRH modulation at a frequency about 10 Hz. Continuous confinement improvement was observed after the mode suppression.