Secondary Beam Magnets for the 200-Bev Accelerator--Conventional or Superconducting?

To exploit fully the capabilities of the 200-BeV Accelerator, many experimental beams must be set up concurrently, and many magnets will be required. The great stiffness of secondary-particle beams having momenta around 100 GeV/c requires long magnets to provide reasonable focal lengths and deflections. The result is a very expensive system of dc beam-transport magnets, and a large expenditure for electric power. Recent spectacular advances in the technology of superconducting (SC) magnets have led us to consider the economics of replacing conventional magnets with equal numbers and kinds of SC magnets. We find the total capital-plus-operating costs of the two systems to be equal, within the accuracy of the analysis. We have, however, compared an optimized system of conventional magnets with a nonoptimized system of SC magnets. Perhaps we would get more physics per dollar with different sizes and numbers of SC magnets. We have not placed a dollar value on one of the major advantages of SC magnets--their higher magnetic-field capability. In some cases the higher fields offer no advantage, in others the advantages might be dramatic. Some beam lines may be shortened about in proportion to the increase in field. The result is less shielding and better usage of the rather expensive facilities. Better measurements can be made on particles having short lifetimes. The development of new SC devices, for example, separators and detectors, will be bolstered by the presence of other SC and cryogenic systems and capabilities.