BEAM POSITION MONITOR FOR THE J-PARC MAIN RING SYNCHROTRON

A BPM system has been developed for the J-PARC Main Ring Synchrotron. A diagonal-cut 'electrostatic' pick-up and a processing circuit with an analog amplifier, attenuator, filter and ADC are adopted. The system expects no active devices in the tunnel to avoid radiation damage. The system aims at a position accuracy of ±0.1 mm. The test using whole system except a cable at the KEK-PS shows good system performance with the position resolution better than ±20 µm. The position accuracy will be attained with careful installation and beam based calibration.