Achievement was made in HT-7 high-temperature plasma experiments from April 11th to June 14th,2004. Discharge pulse length reached 240 seconds.
Five projects in this experiments were long-impulse steady-state plasma technique, plasma core confinement and transport, MHD analysis and control, boundary plasma physics and interaction between plasma and wall. Other projects concerned included non-probe control technique, OMEGATRON diagnostic research, tungsten sample analysis, steady-state plasma control and data processing etc. Breakthrough was made in long-pulse with low-clutter current drive experiment. Discharge time reached 240 seconds.
To obtain the result, complicated improvement was made in HT-7 device. New equipment, such as amphicyclic water-cooling graphite controller, was made and installed; Low-clutter antenna system, poloidal field control technique were modified; New plasma-diagnostic devices were invented.
During the experiment, scientists from the National Institute of Nuclear Fusion, Kyushu University, Massachusette Institute of Technology and Texas University also joined the research, which promoted the international cooperation. This success could not be without the efforts of HT-7 team. (Gao Xiang and Shi Lin report )