NEUTRON DIAGNOSTIC EXPERIMENT FOR ALCATOR C-MOD

The neutron production rate on Alcator C-Mod is expected to peak at 1×1016 n/s for the highest performance experimental pulses. Measurement of the total fusion yield is important for both assessing the experiment and for evaluation of radiological data. The neutron detectors must therefore be capable of accurate measurement over a wide operating regime (1011-1016 n/s from the source). This can be achieved with a series of fission detectors (U235 and U238), capable of operating in both a pulsed and current mode. Computer calculations optimizing the placement of these detectors and also the moderator design are detailed. Calibration of this system will be achieved using a Cf 252 source which will be moved on a track continuously around the major axis. It will also be placed discretely at a number of locations in the torus. MCNP calculations will complement the calibration data. Details of the experimental setup and calibration scheme will be presented.