NEUTRON CAMERA FOR ITER

Based upon JET experience, the measurement of multichannel collimated neutron fluxes and of the neutron spectrum gives time-dependent inform ation on spatial profiles of neutron emission and alpha-particle birth , the total neutron emission (fuel burn-up rate), plasma position, eff ects of plasma instabilities, triton burn-up, ion temperature, and fue l densities. The design for a horizontally viewing neutron camera for ITER is based upon the prototype and upgrade versions of the JET neutr on emission profile monitor and the JET spectrometers. It is proposed that vertically stacked modules are installed in the ITER biological s hield in a fan shaped viewing geometry, aimed at a focal point located at the slit opening of a preshield designed to reduce the streaming n eutron flux. Each module contains a pair of sight Lines with adjustabl e collimation, allowing for multiple detector neutron flux monitoring and neutron spectroscopy over a wide operating range. The modular syst em allows flexibility in detector choice and viewing geometry. (C) 199 7 American Institute of Physics.