Measurements of ITER Fusion Power by Neutron Flux Monitors

The results of the analysis of the uncertainty in measurements of fusion power of the DD and DT plasma scenarios of the ITER tokamak reactor by means of neutron flux monitors are presented. The measurement by three ITER neutron flux monitor systems–Divertor Neutron Flux Monitor (DNFM), Neutron Flux Monitor (NFM), and Micro-Fission Chamber (MFC)–has been simulated. The diagnostic systems considered are designed to measure the total neutron flux and fusion power of ITER plasma. The sources and magnitude of uncertainty in measurements of fusion power and the total neutron flux for various ITER plasma scenarios are examined. The magnitude of the required error in the calibration of the diagnostic detectors is estimated. On the basis of the results of the neutronic analysis and the requirements for the diagnostics set by the International Organization ITER, the expected performance characteristics of diagnostic systems are confirmed. A method to compensate the systematic measurement error of the DNFM due to the vertical displacement of the plasma is proposed.