Design of a Vector Magnet Generating Up to 3 T With Three-Axis Orientation

The low-temperature superconducting (LTS) coils are designed to produce strong magnetic fields at the working temperature of liquid helium. Some kinds of them have been created to produce strong and homogeneous magnetic fields, as in magnetic resonance imaging systems. However, the critical and mechanical parameters of superconducting material limit the performances of the coils. Most of the time, LTS coils are built to produce a homogeneous magnetic flux density in one single direction. Consequently, it is necessary to rotate the subject or the sample, when a study is needed depending on the magnetic field orientation. This is not suitable for special kinds of experiments involving high-temperature superconducting systems or biomedical applications, in which the subject must not be rotated. In order to satisfy these requirements, we have designed a new coil setup. The design was made using a 3-D electromagnetic software in order to calculate the performances of the coils system, to optimize the magnetic field homogeneity and to find a cost effective solution. The first results reported in this paper concern the design of a magnet of three Helmholtz coils, each of which generates a unidirectional magnetic field (x, y, and z). Each Helmholtz coil can generate 1.73 T; thus, the flux density magnitude in the center of system could reach 3 T. The price of the all system, including the cryostat, is around 45 k€.