COMMISSIONING OF THE SOLEIL RF SYSTEMS

The 352 MHz RF accelerating systems for the SOLEIL Synchrotron Booster (BO) and Storage Ring (SR) are being commissioned. In the BO, a 5-cell copper cavity of the CERN-LEP type is powered with a 35 kW solid state amplifier. In the SR, the required RF accelerating voltage (up to 4.4 MV) will be provided by two cryomodules, each containing a pair of superconducting cavities, specifically designed for SOLEIL. The parasitic impedances of the high order modes (HOM) are strongly attenuated by means of four coaxial couplers, located on the tube connecting the two cavities. The first cryomodule is already installed in the SR tunnel, while the second one is being constructed by ACCEL (Germany). These cryomodules are supplied in liquid helium from a single 350 W liquefier and each cavity is powered with a 180 kW solid state amplifier. The RF system commissioning and first operation results are reported. BOOSTER (BO) RF SYSTEM In the SOLEIL BO, a single 5-cell copper cavity of the LEP type (352 MHz) provides the required RF voltage, which is ramped from 100 kV up to 800 kV at the injection rate of 3 Hz. The total needed power, up to 20 kW (15 kW dissipation into the cavity walls and 5 kW into the beam), is supplied by a solid state amplifier, capable of delivering up to 35 kW CW. The solid state amplifier consists in a combination of 147 elementary modules of 330 W, with MOSFET transistor (VDMOS D1029UK from SEMELAB), integrated circulator and individual power supply. All components were designed in house and their fabrication was contracted in the industry. The description of the amplifier and its test results are detailed in reference [1].