Beryllium has been proposed as both a neutron multiplier and as a plasma facing material for fusion reactors, and its neutron cross section up to 15 MeV or so is consequently of considerable importance, particularly for the (n, 2n) reaction. This paper reports on the results of a series of 14 MeV neutron transmission measurements using an NE213 scintillation spectro- meter with three different thicknesses of beryllium shells. The experimental results are then compared with MCNP Monte Carlo calculations using the ENDF/B-VI data set. For all three shells the experimental results lie above those calculated for neutron energies between 8 and 11 MeV, whilst between 1 and 4 MeV they lie below. It is concluded that there are continuing uncertainties in the data.

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