Technique for calculation of three-dimensional magnetic fields in the saddle-shaped superconducting systems of mhd generators with account of frontal part effects

The calculation technique for determining the components of a three-dimensional magnetic field formed by a finite-length dipole magnetic system with an allowance for butt-end faces is described. The components of the magnetic field, induced by an ellipse arc, at an arbitraty point in space are determined from equations obtained on the basis of the Biot-Savart law. The algorithm of calculation of the relative values of the magnetic field components at an arbitrary point of the three-dimensional space, including the current region of the winding, is presented. An analysis of the calculation results shows that the inhomogeneity of the magnetic field in the linear part of the magnetic system does not exceed 7%. In the butt-end zones the magnetic field on the system axis reduces by 5 times. It should be noted that near the butt-end parts there are regions in which the direction of the magnetic field is opposite to that of the magnetic field in the working region of the system. The fringing fields of the dipole magnetic system at a distance less than 2R(R is the inner radius of the dipole magnetic system) may be compared with the field at the centre of the system and are 20-40% of the magnetic field strength at the system centre