set of neutron counters and a pair of scintillators measure the 2.5 Me
V neutron emission produced by the DIII-D tokamak. The neutron counter
set provides a large dynamic range (similar to 7 orders of magnitude)
while the scintillators provide the very fast resolution needed for s
tudying transient events. The counters are absolutely calibrated in si
tu with a Cf-252 source and the scintillators are cross calibrated to
the counters. The historic variations in the emission measured by the
various detectors have been compared and are consistent within the est
imated accuracy of the absolute calibration (15%). In the discharges w
ith the highest emission levels (2.4 x 10(16) n/s), the signals from t
he neutron counters and the scintillators agree well. Comparisons with
other diagnostics also corroborate the neutron measurements. (C) 1997
American Institute of Physics.