MgB2 is the only relatively cheap high-temperature superconductor (Tc = 39 K), but its superconducting characteristics are limited. Nevertheless, it is emerging as a new alternative to the most common superconductor (NbTi) as it now enables the use of cheaper cryogenics without liquid helium.
MgB2 is not easy to use, mainly because mechanical deformation degrades its superconducting properties. SACM has therefore initiated R&D on MgB2. In particular, between 2012 and 2014, research was carried out as part of a thesis entitled “Contribution to the development of MgB2 R&W superconducting magnets cooled by solid conduction”.
The three major steps already completed as part of this R&D are:
? The production of a test station for characterizing samples of MgB2 conductor and testing small coils (Ø < 300 mm). The performance achieved was a temperature of 4 K, a field of 3 T and a current of 600 A.
? The mechanical characterization (Young’s modulus; elastic limit; differential dilatation, etc.), electrical characterization (critical current under the field, resistivity, etc.) and thermal characterization (heat capacity, thermal conductivity, etc.) of many commercial samples. These data are necessary for the design of superconducting magnets.
? The development of coil winding techniques (CEA patent: FR No 13 62981) and coil production: a double pancake coil (50 m of wire) and a solenoid (2 km of wire).