Development of Bismuth Hall sensors for ITER steady state magnetic diagnostics

Hall sensors with bismuth sensitive layer were selected to be implemented on ITER as ex-vessel steady state magnetic sensors. The paper review the design of these sensors and their manufacturing technology, including some alternative options. The sensor prototypes were extensively tested to evaluate their compatibility with the ITER requirements. Dependence of sensitivity of sensors on temperature was found to be very similar for various thickness of the sensitive layer. Results of the neutron irradiation test prove the sufficient radiation hardness of the sensors and show only very modest change of their sensitivity over their full lifetime on ITER. (C) 2017 Elsevier B.V. All rights reserved.