High energy neutron attenuation in concrete

Conclusions

For high energy neutrons (E > 20 Mev) produced by proton charge exchange, the flux attenuation follows an exponential law for concretes of various compositions in thicknesses exceeding 20–40 cm. The experimental results disprove the widely held idea that the neutron half-value layer in the energy range studied is inversely proportional to concrete density [7, 8]. Such an erroneous idea sometimes gains seeming economic advantage for the use of high density concrete because of savings in area and volume, and better building components on the whole [8].

On the basis of the experimental results obtained, it is possible to say that the use of any high density concrete will lead to an increase in shielding cost in comparison with shielding of ordinary concrete (Table 3). Consequently, the use of special high density concrete may be justified in special cases, for example, in the reconstruction of existing accelerator buildings.