A lot of good neutron science

Eurofusion January 16th 2018

Participants in the WP JET3 Annual General Monitoring Meeting in Culham on December 4-7, 2017. Picture: Copyright protected by the United Kingdom Atomic Energy Authority)

Scientists at the Joint European Torus (JET) have been working feverishly to prepare experiments which allow the improved measurements of neutrons for the planned tritium (T) and deuterium-tritium (DT) campaigns. Those experiments are scheduled in 2019 – 2020 but the preparations have been ongoing for years now. The fusion experts have developed new detectors which are already in place to study the neutron streaming through penetrations in the biological shield and to investigate the activation and damage they induce in the material. Such observations are of extraordinary importance for ITER because they can prove that the tools used in the ITER design are valid and appropriate.

We will be ready!

“I was excited to see the results achieved this year, we produced a lot of good neutron science. Also, after a considerable preparatory effort, we will be ready for the T and DT campaign” says Project Leader Paola Batistoni. One of the most important achievement is the calibration of JET neutron yield monitors at 14 MeV neutron energy. She admits that it has been quite challenging to insert a neutron generator inside the JET tokamak with the help of the remote handling system, to calibrate the neutron detectors. This came with the complex equipment of active detectors, power supply units, and electronics. However, the measurement accuracy in the calibration is better than the target value of ten percent.

Gaining experience for ITER

Additionally, neutron detectors have been installed around the tokamak. They have already provided time dependent measurements of dose rates during operation and in the following shutdown. The preliminary results of the first simulations show that the calculated shutdown dose rate is in remarkable agreement with measurements. More than sixty scientists have discussed those notable results during the Annual General Meeting of the JET DT Technology Project at the end of this year. Among those experts were representatives of fusion organisations worldwide such as Mike Loughlin (Nuclear Integration coordinator in ITER), Dieter Leichtle and Marco Fabbri (Nuclear Integration coordinators in F4E) as well as Robert Grove and Scott Mosher from Oak Ridge National Laboratory and Tim Bohm from the University of Wisconsin Maddison.

Team excitement was palable

At times during the meeting the team excitement was palpable because we finally see that the initial effort is producing a good harvest”, concludes Paola.