The placing of many large superconducting magnets in a limited space

The problem of minimizing the space needed to house two or three superconducting magnets was studied. Dipolar fields were used to approximate the stray fields. Field contours of a single dipole mu are reviewed. The three-dimensional contour surface is discussed in terms of its intersection with planes parallel to a base plane containing mu. The area within a field contour H in the base plane was numerically determined to be 142.55 m2[(mu/mu 0)(H0/H)]2/3 where mu 0 = 10(9) erg/G and H0 = 5 G. For the contours within planes parallel to the base plane, the contour area and its intercepts with the planar x and y axes are given as a function of the distance from the base plane. For two dipoles at one site and for a given mechanical stress, the torque-free orientations allow closer spacing. Field contours for the four torque-free orientations are given for mu 1 = mu 2. For one zero-torque configuration (mu 1 and mu 2 antiparallel, but perpendicular to the line joining them) and for a mutual force of 667 N (150 lb), the 5-G contour area is only 36% greater than that for a single dipole. General expressions for the forces, torques, and field gradients for two dipoles are given. Torque-free cases of three superconducting magnets (two of which are identical) at one site are described. Contour plots of the linear arrangements of the magnets as well as of two symmetrical triangular arrangements (corner angle is either 70.5 or 109.5 degrees) are given.