Fusion Power Measurement at ITER

The measurement of fusion power, i.e., total neutron emissivity, will play an important role for achieving the goals of ITER project, in particular the fusion gain factor Q related to the reactor performance. The article gives overview of the neutron diagnostics being developed for ITER. Particular attention is given also to the development of the neutron calibration strategy whose main scope is to achieve the required accuracy of 10% for the measurement of fusion power. Neutron Flux Monitors located in diagnostic ports and inside the vacuum vessel will measure ITER total neutron emissivity, expected to range from
$10^{14}~\mathrm {n}/\mathrm {s}$
in Deuterium—Deuterium (DD) plasmas up to almost
$10^{21}~\mathrm {n}/\mathrm {s}$
in DT plasmas. The neutron detection systems as well all other ITER diagnostics have to withstand high nuclear radiation and electromagnetic fields as well ultrahigh vacuum and thermal loads.