STUDY OF MAGNETIC FIELD IMPERFECTIONS OF KOLKATA SUPERCONDUCTING CYCLOTRON

Analysis of the magnetic data obtained during the magnetic field mapping of Kolkata superconducting cyclotron showed imperfections in the main magnetic field. Since the main magnet of the superconducting cyclotron is three fold rotationally symmetric, any deviation from this symmetry creates imperfections in the magnetic field. Generally, 1st and 2nd harmonic components are inherently present in the field due to assembling errors in iron/coil. A major portion of these imperfections is attributed to the misplacement/tilting of the iron pole tip with respect to coil. The error in positioning of main superconducting coil with respect to surrounding iron produces another imperfection. Pole tip deformation due to rise of temperature produces field imperfection. This paper reports the various possible sources of imperfection in general and their estimation. The calculation was compared with measured data to find out the actual cause of imperfections and necessary corrections have been carried out.IMP;Chinese Academy of Science