Superconducting dipole moment correction coils for a free-flying version of ASTROMAG

Abstract

ASTROMAG is a particle astrophysics experiment which will operate in space for a period of two years or more. Momentum and charge resolution of cosmic rays is achieved using particle detectors in a magnetic field. In the ASTROMAG experiment, this magnetic field is provided by a pair of superconducting solenoids. The ASTROMAG superconducting magnet is supposed to have a zero net magnetic dipole moment so that magnetic torques introduced to the space craft are kept at a low level. Dipole moment correction coils, which can provide up to 11,000 Am 2 of correction in the Z direction and 7,000 Am 2 of correction in the X and Y directions, appear to be practical using superconducting correction coils which are mounted on the superfluid helium tank in a region 0.5 meters wide halfway between the main ASTROMAG coils. The superconducting dipole moment correction coils should be capable of reducing the ASTROMAG magnet net dipole moment to 100 Am −2 or lower.