Cavity beam position monitors
Beam position monitors are essential devices for the control of charged particle beams. The beam orbit within an accelerator must be precisely known, for machine protection, beam alignment with respect to magnetic elements, dispersion measurement, lattice model vertication, orbit correction, and feedback. The BPMs deployed at ATF2 are the result of approximately a decade of research into high resolution cavity based BPMs.
There are two common types used denoted by their resonant frequency; C and S-band. In total there are 40 high performance cavity BPMs installed at ATF2, the largest system of its class in the world. The John Adams Institute at Royal Holloway is responsible for the S-band electronics and the entire readout digital and software system for both the C and S-band systems. We are also actively collaborating with KEK, SLAC and KNU scientists to develop more advanced systems, such as higher resolution or faster response time (latency). This work will lead onto the BPM systems required by very challenging machines such as CLIC.
Technical details can be found on our collaborative web pages; Cavity beam position monitor systems TWiki.