Beam position monitor and its calibration in J-PARC LINAC

The beam commissioning of J-PARC LINAC has been started in November 2006. Beam position monitors (BPMs) which had been calibrated on the bench setup with a scanning wire, take beam-based-calibration method in order to enable the beam to pass at the centre of a quadrupole magnet (Q-magnet). In this presentation, the installed BPMs and their calibration methods are described.