Shimming of Magnets

  The addition of small pieces of magnetizeable iron (a shim is a piece of corrective material) in order to achieve desirable properties of a magnetic field,

e.g. to approximate better

• - constant deflection power ( Errors in Track Reconstruction),
• - field smoothness on the edges of pole faces,
• - small field gradients in the neighbourhood of a symmetry plane,
• - cylindrical symmetry for cylindrical pole faces in a C-shaped yoke,
• - correction of imprecisions of coil mounting.