Conceptual Design Studies on the Magnet System for the Volumetric Neutron Source

A Volumetric Neutron Source (VNS) is proposed as a compact tokamak to serve as a qualification testbed for fusion in-vessel components, breeding blanket in particular. The main goal is to determine the minimum size of the machine while maximizing the Neutron Wall Load (NWL). This paper discusses the design parameters and constraints involved in specifying the magnetic cage for VNS. The focus of the study is on sizing the TF (toroidal field) coils and related structures with the plasma magnetic field, as well as assessing how various design constraints influence the machine performance at higher magnetic field strengths. In particular, the trade-off between TF neutron heat load and dose and shielding efficiency. A very preliminary (and still evolving) design point for VNS is presented and discussed.