STATUS OF THE NEUTRON DIAGNOSTIC EXPERIMENT FOR ALCATOR C-MOD

The Alcator C-Mod experiment is expected to produce neutrons at a rate of up to 1 X 10(16) n/s during its highest performance operation. The global neutron detection system must provide accurate measurement of this production over the full operating regime of the experiment, 10(11)-10(16) n/s. This is accomplished using a series of uranium fission detectors enriched in U-235 of staggered sensitivity. These are distributed in two moderator assemblies. A BF3 detector is added to each moderator to cover the lowest operational range. Preliminary calibration of the system has been accomplished using a 65.4 mug Cf-252 Source placed inside the Alcator C-Mod vacuum vessel. The system design and calibration is discussed herein.