Upgrading the General Atomics Radio-Frequency Sources for Higher Power

Several years ago the Princeton Plasma Physics Laboratory (PPPL), Oak Ridge National Laboratory (ORNL) and General Atomics (G.A.) formed a collaboration to return the three G.A. radio-frequency (RF) sources to service, and to upgrade the two higher frequency range RF sources to have larger 2.5 megawatt power tubes for greater output power. To date, the 60 Mhz source is routinely operated into G.A.'s Doublet III D (DIIID) experiment at a power level up to 1 MW. The power tube upgrade for one of the higher frequency sources has been completed and has been tested to 1.4 MW into a test load and 750 kW into plasmas. Preparations for the tube upgrade for the other higher frequency source is now underway.