Measurements of the Beam Phase Response to Correcting Magnetic Fields in PSI Cyclotrons

The cyclotron-based proton accelerator facility (HIPA) at PSI is presently operated at 1.3-1.4 MW beam power at a kinetic energy of 590 MeV/u to drive the neutron spallation source SINQ and for production of pion and muon beams. Over the years HIPA facility has developed towards increase of the delivered beam current and beam power (0.1 mA in 1974 till 2.2 mA in 2010). During the last few years several upgrades of the Ring cyclotron field correction and beam phase monitoring systems were made. RF voltage was also increased. In order to test the performance of the upgraded system the phase response measurements were carried out.