Numerical simulations of in-situ neutron detector calibration experiments on the Tokamak Fusion Test Reactor

Accurate determinations of fusion neutron yields on the TFTR require that the neutron detectors be absolutely calibrated in-situ, using neutron sources of known strengths. For such calibrations, numerical simulations of neutron transport can be powerful tools in the design of experiments and the study of measurement results. On the TFTR, 'numerical calibration experiments' have been frequently used to complement actual detector calibrations. We present calculational approaches and transport models used in these numerical simulations, and summarize the results from simulating the calibration of 235U fission detectors carried out in December 1988. 12 refs., 9 figs., 6 tabs