EXPERIENCE WITH A BROADBAND VITROPERM-FILLED CAVITY AT THE SYNCHROTRON COSY

At the Cooler Synchrotron COSY, a broadband cavity using the magnetic alloy VitroPerm replaced the existing ferrite cavity in routine operation for more than 8400 hours. The frequency range of the VitroPerm cavity covers 0.4 to 8 MHz without tuning loop. This allows the simultaneous combination of the fundamental together with higher harmonics during the acceleration cycle. Compared to a sine-wave for acceleration, the combination of fundamental and 2nd harmonic improves capture after injection, and the number of particles in flat top of COSY was found to be increased by about 20 percent. The accelerator COSY allows super-cycles and runs more than 7000 hours per year. Therefore, the control and synthesis of the waveforms and the preparation of the ramping functions needs to support this. To ensure reliable operation, the control of the 7 signal processors is based on a VME system running under the operating system Linux.