DEVELOPMENT OF RF SYSTEM FOR K500 SUPERCONDUCTING CYCLOTRON AT VECC, KOLKATA

The 3-phase rf system of Superconducting (Sc) cyclotron has been developed in the frequency range 9 – 27 MHz with amplitude and phase stability of 100 ppm and ±0.5o respectively. Each dee along with half-wave coaxial cavity develops peak voltage of 100kV having fed with rf power (~80kW) from each of the three high power final rf amplifiers. Like main Dee-cavity, each amplifier is tuned by moveable sliding short. Each of the four identical Bridge-T network in the grid are driven with maximum power of 150 watts. The amplifier, based on Eimac 4CW#150000E tetrode and operated in class-AB mode with power gain 22 dB, requires dc power supplies (P/S