Beam size effects on beam position measurements in proton synchrotron

The three-dimensional surface electric charge method has been applied to calculate the effects of the beam size on the beam position measurements. We confirmed that the change of the beam size led to beam position errors. The calculated results were compared with experimental data, indicating the validity of the simulation. The output signal ratio of beam position monitor was smaller when the beam size was large in the horizontal direction. The proposed method can estimate the effects of the beam size when a beam cross section is given.