The Test Bench for the Power Amplifiers of the Spiral-2 Sc Linac

The high current driver accelerator of the SPIRAL 2 project uses independently phased SC resonators working at 88 MHz. Solid state power amplifiers equipped with circulators are foreseen to drive the cavities with widely ranging conditions of beam loading. These power devices are developed by industrial companies and a test bench has been studied and manufactured to test the prototypes, to commission all the units before their installation on the accelerator and to be used to test repaired modules. Even if designed to be used at 88 MHz, the test bench can be used at higher frequencies too. The poster describes the test bench as well as the results on the first amplifiers bought for the cryomodule power tests. BEAM LOADING AND POWER REQUIREMENTS The Spiral 2 driver [1] will accelerate ion beams ranging from few tenths of uA to several mA, corresponding to a wide range of beam-loading. A fixed coupler is foreseen for the SC cavities for reliability reasons, with 4.5E5 and 1.2E6 nominal Q loaded factors for the low and high beta families. These values correspond to overall optimal matching conditions at maximum beam loading. Beam dynamics simulations [2] at maximum deuteron current give the amount of beam loading of each cavity as shown in Figure 1 .