A Neutron Camera for ITER

摘要

Based upon JET experience, the measurement of multi-channel collimated neutron fluxes and of the neutron spectrum gives time-dependent information on spatial profiles of neutron emission and alpha-particle birth, the total neutron emission (fuel burn-up rate), plasma position, effects of plasma instabilities, triton burnup, ion temperature and fuel densities. The design for a horizontally viewing neutron camera for ITER is based upon the prototype and upgrade versions of the JET neutron emission profile monitor and JET spectrometers. It is proposed that vertically stacked modules are installed in the ITER biological shield in a fan shaped viewing geometry, aimed at a focal point located at the slit opening of a pre-shield designed to reduce the streaming neutron flux. Each module contains a pair of sight-lines with adjustable collimation, allowing for multiple detector neutron flux monitoring and neutron spectroscopy over a wide operating range. The modular system allows flexibility in detector choice and viewing geometry.