Transverse stress on Nb/sub 3/Sn conductors in high field NMR magnets

For a thin coil section of a solenoidal magnet, the relationship between the reduction in axial stress and the reduction in tangential stress for a given quantity of lumped reinforcement is determined. The axial compression in solenoids originates toward the end of the solenoid in the region of greatest radial field. For the axial load to accumulate on the conductor in the midplane, the reinforcement will be placed in compression axially. The result is a redistribution of the axial load and a reduction of the axial stress on the conductor. It was a primary objective of the present work to examine this mechanism and to determine the effectiveness of the lumped reinforcement in reducing the axial stress on the windings. The general picture of axial stress in long thin solenoids which has emerged in the course of this investigation is described. The axial and radial stress distribution in a coil of a high field magnet is computed and related to the performance of the Nb/sub 3/Sn conductor in the coil.<>