Observation of quadrupole mode frequency and its connection with beam loss

Recent simulation results imply that the number of particles in a high intensity synchrotron is limited by the resonance crossing of coherent mode oscillations, not by the incoherent one. In order to verify it, we measured the tune shift of quadrupole mode oscillations in HIMAC at National Institute of Radiological Sciences (NIRS) to show the connection with beam loss. In this paper, we discuss signals observed in a coasting beam. We also present the numerical calculation of envelope motion for a bunched beam.