XFEL Beam Position Monitor - RF Cavity Type
Features
RF Cavity type monitor for SACLA
The RF Cavity Beam Position Monitor has been developed for use on SACLA, a compact 8GeV X-ray Free Electron Laser located at SPring-8, Japan, with the SACLA project team. These monitors are installed in the accelerator and undulator sections of SACLA as well as in the experimental beamline, a total of 56 units installed.
The RF cavity monitor was developed as a very high resolution beam position monitor to measure the beam position very accurately.
It uses a TM110 dipole resonance field excited in a cylindrical cavity by the electron beam. The position detection cavity and an additional TM010 monopole cavity (the reference cavity) is used to determine the beam charge and phase reference. The two cavities have the same resonance frequency.
Position resolution has been measured as less than 0.2µm.
The temporal resolution of the beam arrival time was measured as 25fs.