Parametric optimization of neutron drum counter

We optimize the efficiency of neutron counter designs for 208-1 drums when counting totals neutrons by using MCNP. Design parameters, including the number of 3He tubes and the tube pitch, depth, and gas-fill pressure, were investigated. Both cylindrical and rectilinear geometries with and without cadmium liners were examined. Fission spectra from both 240Pu and 252Cf were modeled as isotropic point sources located in the geometric center of the detector cavities.