First thermo-structural vacuum barrier design for the EU DEMO feeders

The vacuum barrier (VB) is designed to separate the feeder into two distinct vacuum regions: the main cryostat vacuum and the feeder vacuum. This separation enhances thermal insulation and facilitates maintenance and access to feeder components. Beyond sustaining pressure under both normal operation and potential malfunctions, the VB also minimizes heat transfer from the environment to low-temperature systems. This paper details the optimization process of an initial VB design, utilizing a Radial Basis Functions-based mesh morphing approach. Shape variations were applied concurrently to structural and thermal simulations, enabling parameterization of the complex, coupled nonlinear system where the structural model withstands both pressure and temperature loads. The optimal VB configuration, meeting structural and thermal criteria, was ultimately identified through response surface optimisation.