NATIONAL PHYSICAL LABORATORY Calibration and Monte Carlo Modelling of the NPL Long Counters
نویسندگان
چکیده
An extensive programme was successfully carried out during the 1995 to 1998 NMS programme to recalibrate and model by Monte Carlo simulations the characteristics of two NPL long counters that are routinely used to standardise neutron fluences [Ta98,Ta00] for neutron energies above 500 keV. The present work is a continuation of it in that the counters responses and effective centres have been measured and simulated for a neutron energy of 22.8 keV using an antimony-beryllium (SbBe) photon-neutron source. The neutron source emission rate was measured using the manganese sulphate bath technique. The efficiency and effective centres of both counters have been measured in a low scatter facility at NPL and calculations have been performed using MCNP4C.
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