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Based upon JET experience, the measurement of multichannel 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 burn-up, 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 the 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 preshield 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.

A high count rate 4w 8-y coincidence counting system for the determination of absolute disintegration rates of short half-life radionuclides is described. With this system the dead time per pulse is minimized by not stretching any pulses beyond the width necessary to satisfy overlap coincidence requirements. The pulse widths in the beta-ray (8), gamma-ray (y), and coincidence channels are extendable and not fixed. Therefore, the dead-time for each channel is measured and recorded along with the gross count data during each counting period.The equations used to correct for the 8,y , and coincidence channel dead times and for accidental coincidences are presented but not rigorously developed in this paper. Experimental results are presented for a decaying source of 56Mn initially at 2 x 106 d/s and a set of 60Co sources of accurately known source strengths varying from 103 to 2 x 106 d/s. A check of the accidental coincidence equation for the case of two independent sources with varying source strengths is presented.