A High Field Tokamak Neutron Source Facility

Abstract

Fusion creates more neutrons per energy released than fission or spallation, therefore DT fusion facilities have the potential to become the most intense sources of neutrons for material testing. An Ignitor-like device, that is a compact, high field, high density machine could be envisaged for this purpose making full use of the intense neutron flux that it can generate, without reaching ignition. The main features of this High Field Neutron Source Facility, which would have about 50% more volume than Ignitor, are illustrated and the R&D required in order to achieve relevant dpa quantities in the tested materials are discussed, in particular the adoption of superconducting magnet coils. Radiation damage evaluations have been performed by means of the ACAB code, showing the potential of high field, neutron-rich devices for fusion material testing. Few full-power months of operation are sufficient to obtain significant radiation damage values (in terms of dpa) of large size samples (~m³). The setup of a duty cycle for the device in order to obtain such operation times is discussed. The problem of radiation damage to the insulator of the Toroidal Field Coils has been explored. Two strategies for mitigating damage to the TF coil insulators have been demonstrated, and it is likely that both will need to be implemented to ensure the survival of the insulating material for the lifetime of the tokamak.