Superconducting unclosed shields for improving homogeneity of the magnetic field in magnetic systems.

The homogeneity of the magnetic field is a very important task for such practical applications as MRI, NMR spectroscopy and particle accelerators (electron cooling systems etc.). An axisymmetric solenoid is often used as a source of the magnetic field. This work presents the experimental results of the influence of the superconducting unclosed shield on homogeneity of the solenoid magnetic field. The developed mathematical model adequately describes the shielding of the radial component of the external non homogeneous field. These results open up an opportunity of designing the efficient superconducting unclosed shields to form highly homogeneous magnetic fields in big volumes. The results of this work are supposed to be used for the electron cooling system of the NICA (the Nuclotron-based Ion Collider fAcility) which is being developed at JINR.