The Transverse Feedback System for the CERN PS Booster

With the operational beam intensity in the PSB continuing to increase, transverse stability will soon become a limiting factor. To damp transverse instabilities, a wide band feedback system has been designed and built, and it is being installed at present. It consists of eight independent systems (four rings, two planes), based on the usual scheme (position sensor, and deflector located at an odd number of betatron quarter wavelengths). Specific features of the PSB system are: large bandwidth (> 50 MHz), limited by easily modifiable filters; continuous and automatic delay tracking (by digitally controlled delay lines) coping with the proton velocity variations (ß ¿ 0.31 to 0.84); automatic suppression of the closed-orbit induced signal, allowing considerable savings in the power rating of the output amplifiers. The paper describes the system and its characteristics.