Magnetic median plane measurement in the central region of superconducting cyclotron (SCC)

The magnetic median plane in the cyclotron often does not coincide with the geometrical mid-plane of magnetic system. This leads to additional beam losses owing to small axial focussing of the beam in the centre of cyclotron. However we have observed vertical deviation of the beam centre from the geometrical median plane during beam tuning. So the equipment based on search coil is developed and used for magnetic median plane measurement in the central region of the superconducting cyclotron (SCC). The paper describes the design, fabrication and results of magnetic median plane measurement. (author)