Fusion Science and Technology / Volume 51 / Number 2T / February 2007 / Pages 208-212
Technical Paper / Open Magnetic Systems for Plasma Confinement
In GAMMA 10, the upgrade program of high power plug and central ECRH have started for the study of the physics of plasma potential and the demonstration of high plasma performance proving the tandem mirror advantage. A new high power (upgrade) gyrotron has been developed in collaboration with JAEA from 2003 for this purpose and now three upgrade gyrotrons were installed in GAMMA10. The first gyrotorn in 2004 outputted about 500 kW power at the gyrotron window, corresponding to 400kW injection power to plasma. In 2005, the power of 570 kW at the window was obtained from the second one, which was improved mainly in mode converter. These gyrotron were applied to plug cells and a new record value of ion confining potential c = 3kV was obtained at 470 kW injection, which is four times higher than the previous value before 2003. For the central ECRH system, the upgrade of DC power supply was conducted using the DC power supply from JFT-2M ECH system and the system outputted 400kW at MOU out with the upgrade gyrotron. The central ECRH has been conducted with the combination of the new efficient antenna, transmission line and the upgrade gyrotron, and the initial experiment resulted Te 500eV.