HTS coils without HTS tapes, free-surface liquid metal walls and their fusion and non-fusion applications
Date : Jeudi 29 septembre 11:00 – Duree : 1 heure Lieu : CNRS Alpes – Salle de séminaire – Bâtiment A – 25 avenue des Martyrs – 38000 Grenoble
Orateur : Francesco A. VOLPE
Résumé :
Renaissance Fusion is a Grenoble-based nuclear fusion start-up that synergistically combines three main pillars : the stellarator, High Temperature Superconductors (HTS) and liquid metal walls. The stellarator magnetically confines fusion plasmas similarly to a tokamak, but without needing a current in the plasma. As a result, it is more stable and inherently steady state, but requires more complicated external coils. At Renaissance Fusion we dramatically simplify the coils by (1) finding solutions on simplified coil-winding-surfaces and by (2) streamlining the coil manufacturing. In fact, we completely bypass the paradigm of HTS tapes and cables. Instead, we directly deposit and pattern multi-layer HTS coils on vacuum vessels or other wide surfaces. Laser-ablated grooves geometrically constrain the supercurrents as to generate stellarator magnetic fields. This finds application in several other areas, from magnet undulators for synchrotrons to superconducting magnetic energy storage. Basically, we are developing large printed circuits, but cylindrical and superconducting. Flowing mesoscale liquid metal walls will fully cover their interior to shield structural materials and delicate HTS from fusion neutrons, as well as to extract heat and breed one of the fusion fuels : tritium. Experimental evidence will be presented of free-surface liquid metal flows adhering to the interior of cylindrical chambers by means of electromagnetic and centrifugal forces. Passive and active magnetohydrodynamic stabilization was obtained, as well as initial results toward feedback stabilization. Optimization results will be presented in the areas of plasma equilibrium, coil forces, economic power-plant sizing and neutron shielding, and a remarkably simple Tritium extraction technique will be presented. Research needs, job openings and areas of possible collaboration will also be discussed, with emphasis on imminent HTS, liquid metal and neutronic experiments.
