Testing of Superconducting ReBCO Prototype coils for EPOS Stellarator

The EPOS stellarator, a compact device for confining electron-positron plasmas, will leverage high-temperature superconductors (HTS) to generate a highly optimized toroidal magnetic field.

To achieve this, we will employ non-planar, non-insulated coils made from rare-earth barium copper oxide (ReBCO) tapes. Prototypes were tested this summer of planar coils on a coldhead cooled to 20K by a closed-cycle helium compressor system.

The prototype planar coils were able to produce a magnetic field of up to 3T with a sustained current of up to 400A and maximum current of 800A. These values resemble the values required for the Stellaroator.

The design of a new test stand was required to test multiple of these planar coils in series, and later for the on-planar Stellarator coils. The engineering design of the test stand and the two clamping systems to be tested on the stand are presented.

While testing the coils, we also sought to test several diodes to possibly use as cryogenic temperature sensors in the EPOS experiment. This was done by reading the voltages across diodes through an Arduino.