Analysis of Transmutation of Candidate Sensitive Layer Materials of Hall Detectors under DEMO Like Neutron Fluxes

• Published in: Fusion engineering and design 2020-06, Vol.155, p.111670, Article 111670
• Main Authors: Kovarik, Karel, Entler, Slavomir, Duran, Ivan, Eade, Tim
• Format: Article
• Language: English
• Subjects: DEMO; Detectors; Diagnostic systems; Fluence; Hall effect; Hall sensor; Neutron flux; neutron irradiation; Neutron spectra; Plasma currents; Position measurement; Sensors; Transmutation
• ISSN: 0920-3796; 1873-7196
• DOI: 10.1016/j.fusengdes.2020.111670

•Calculation of neutron induced transmutation using latest neutron fluxes and spectra at positions dedicated for Steady-state magnetic diagnostics of DEMO•Comparison of transmutation of 7 most promising candidate elements for Hall Probe sensing layer Steady state magnetic sensors based on the Hall effect are one of the candidate diagnostic concepts for measurement of plasma current, plasma position and shape on the future demonstration fusion power reactor (DEMO). Design of any diagnostic component has to consider the foreseen high neutron fluences which will be accumulated over DEMO’s operational time. The total DEMO life time neutron fluence is expected to reach up to 1026 m-2 for in-vessel locations. At these levels of neutron load, transmutation of materials becomes an effect which has to be considered. Neutron spectra and flux rates were determined using MCNP6 code for a selected location considered to be instrumented by the Hall sensors on DEMO. Using these neutron spectra, inventory simulations were conducted with FISPACT-II code for a set of materials presently considered for sensitive layers of the DEMO Hall sensors. Resulting information on evolution of material composition of Hall detectors along the DEMO operation is summarized. Comparison of simulations of various irradiation time patterns e.g. continuous versus more realistic DEMO campaign regime is presented.