On the absolute calibration of neutron measurements in fusion reactors

• This paper focuses on the issues of obtaining the absolute calibration of neutron measurements in fusion reactors, including also ITER and DEMO.
• Such absolute calibration is required to provide the fusion power, to account for burnt Tritium, and to derive plasma ion parameters.
• The calibrating procedure adopted so far appears to be very complex when applied in ITER, and probably unviable in DEMO and in the future reactors.
• An alternative solution based on the neutron activation technique using long-lived radioisotopes is proposed in this paper.
• Potential reactions are investigated and the expected activity levels are calculated for several materials in ITER.
• A test in JET is proposed.

This paper focuses on the issues of obtaining and maintaining the absolute calibration of neutron measurements in fusion reactors, including also ITER and DEMO. Such absolute calibration is required to provide the fusion power, to account for burnt Tritium, and to derive plasma ion parameters. The usual calibrating procedure adopted so far in fusion devices appears to be very complex already when applied in ITER, and most probably unviable in DEMO and in the future power plants. An alternative solution based on the neutron activation technique using long-lived radioisotopes is proposed in this paper. Potential reactions are investigated and the expected activity levels are calculated for several materials in ITER. A test in JET is proposed.