Heat Shield Design for Optimized Stellarator

EPOS (Electrons and Positrons in an Optimized Stellarator) is a collaborative engineering‑physics effort to confine electron–positron plasmas in a compact, optimized stellarator. The device employs rare-earth barium copper oxide (ReBCO) coils at 20 K to produce the required confining magnetic field. To achieve this temperature, we designed a heat shield to intercept radiative loads from the 300 K vacuum chamber walls--validating the design with both Finite Elemental Analysis (FEA) and heat transfer calculations. A Stefan-Boltzmann model was used to show that, without a shield, the coils would absorb approximately 72.03 W, whereas the integration of the designed heat shield would reduce this to just 0.08 W. Using 6061-T6 aluminum, the cylindrical body is roll-formed, welded together, and bolted onto a bottom frame. Indium gaskets join 10 side and 4 top access ports to maximize thermal contact. Structural FEA was used to calculate gravity, thermal, and transport deformation, predicting max values of 0.10 mm, 4.23 mm, and 0.07 mm respectively. Our radiative and structural calculations show that the heat shield keeps the coils well within the cryocooler's capacity—making sustained high‑field plasma experiments in the EPOS stellarator possible.