The power output of fusion devices is measured in terms of the neutron yield which relates directly to the fusion yield. JET made a transition from Carbon wall to ITER-Like Wall (Beryllium/Tungsten/Carbon) during 2010–11. Absolutely calibrated measurement of the neutron yield by JET neutron monitors was ensured by direct measurements using a calibrated 252Cf neutron source (NS) deployed by the in-vessel remote handling system (RHS) inside the JET vacuum vessel. Neutronic calculations were required in order to understand the neutron transport from the source in the vacuum vessel to the fission chamber detectors mounted outside the vessel on the transformer limbs of the tokamak. We developed a simplified computational model of JET and the JET RHS in Monte Carlo neutron transport code MCNP and analyzed the paths and structures through which neutrons reach the detectors and the effect of the JET RHS on the neutron monitor response. In addition we performed several sensitivity studies of the effect of substantial massive structures blocking the ports on the external neutron monitor response. As the simplified model provided a qualitative picture of the process only, some calculations were repeated using a more detailed full 3D model of the JET tokamak.
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Materials Science(all)
- Nuclear Energy and Engineering
- Mechanical Engineering
Snoj, L., Lengar, I., Čufar, A., Syme, B., Popovichev, S., Batistoni, P., & Conroy, S. (2016). Neutronic analysis of JET external neutron monitor response. Fusion Engineering and Design, 109-111(PartA), 99 - 103. https://doi.org/10.1016/j.fusengdes.2016.03.046