Design of a Low-Temperature Superconducting coils system generating up to 3 T in a 10 cm bore diameter with 3 axis orientations
Résumé
The LTS superconducting 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 (MRI). Furthermore, the critical and mechanical parameters of superconducting material limit the performances of the coils. Most of the time, the LTS coils are also build to produce a homogeneous magnetic flux density in one single direction |B|=|Bx|. Consequently, it is necessary to rotate the subject or the sample, if we want to make a study depending of the magnetic field orientation. This cannot be suitable for special kinds of experiments involving HTS systems or biomedical applications where the subject would need to be rotated. To find an answer to this problem we have designed a new coils setup that will satisfy these requirements. Hence, we are working on orientation along 3 axes of a strong magnetic flux density. The design has been made using a 3-D electromagnetic software in order to calculate the performances of the coils system, to optimize the homogeneity and to find a cost effective solution. The first results reported are for a three Helmholtz coils system where each axis is placed following the Cartesian coordinates: x, y, z. This system is designed for 3 T of magnetic flux density at the center of the coils and a peak value on the coils around 7 T, for an operating current of 160 A in each coil.