Total leakage multiplication experiments and analysis on a combined beryllium sphere

The given work concludes a series of total neutron leakage multiplication experiments performed in the RRC ‘Kurchatov Institute’ with several perspective neutron multiplying materials, such as U, Th, Bi, PB and Be. It is devoted to the measurements and calculations for seven beryllium spheres combined from the spherical shells belonging to the USA, PRC and RF. The total leakage multiplication measurements were carried out using the total absorption detector (TAD) method with the use of a boron tank. The calculations were carried out by the MCNP/4A transport code with FENDL-1 and JENDL-FF data. A comparison of experimental and calculated results has shown good agreement (within the experimental uncertainty ∼ 3–4%) of the leakage multiplication values for all the spheres covering the range of beryllium layer thickness from 3 to 20 cm.