Pre-conceptual study of the European DEMO neutron diagnostics

This paper discusses the pre-conceptual design of the European DEMO neutron diagnostics aimed at the measurement of the fusion power, the plasma displacement and the fuel ion ratio for plasma burn control. The design has been based on the European DEMO design concept with a single divertor and on the so-called DEMO1 plasma scenario but limited only to the steady phased of the discharge. The suggested neutron diagnostics consist of neutron activation systems, fission chambers and vertical and horizontal collimated neutron flux monitors with spectroscopy capabilities. The fusion power can be measured with an accuracy of 1% with a time resolution of one tenth of the energy confinement time and the plasma displacement with a time resolution of 1 ms. Central ion temperature and fuel ion ratio instead can be measured with a time resolution of about 1 s. Calibration and interfacing issues are discussed.