Facility wide real-time beam loss monitoring & control using FPGA technology

The ISIS facility based at Rutherford Appleton Laboratory, Chilton, Didcot, UK is currently the worlds brightest pulsed neutron spallation source producing a beam to target power of ~160 kW. Whilst operating at high beam powers it is critical that beam loss around the facility is monitored to ensure that component activation is kept to reasonable levels. Beam loss is detected using 82 gas ionisation chambers distributed throughout the Injector, 800 MeV synchrotron, the extracted proton beamline and the new extracted proton beamline for the second target station (TS2). This paper introduces the new beam loss display and beam trip systems which use a modern field programmable gate array (FPGA) design to provide real time monitoring, beam loss data logging and faster beam trip reaction time. Bench testing has proven the new system.