Design study of superconducting magnets for uniform and high magnetic force field generation

Magnetic force is one of the most promising tools to realize a virtual micr ogravity environment on earth. It has recently been found that the growth o f protein crystals might be affected by microgravity offing to the suppress ion of the convectional flow. We started the development of superconducting magnets for the generation of uniform and high magnetic force fields to su ppress convectional flow. As it was not clear what configuration of superco nducting coil could generate most effectively high magnetic force fields, w hile they maintain their uniformity. For this purpose, we used a nonlinear programming method. The results obtained clarified that a magnet whose inne r coil is longer than the outer one can generate more uniform and higher ma gnetic force fields in a long sample space. A superconducting magnet generating a magnetic force field of 240 T-2/m has already been constructed with NbTi conductors at the Tsukuba Magnet Labora tory. We have also completed the design of a superconducting magnet compose d of Nb3Sn and NbTi conductors to generate uniform magnetic force fields up to 882T(2)/m.