Time-dependent neutron field experimental set-up at the pulsed neutron generator in the Institute of Nuclear Physics

The pulsed neutron in the Institute of Nuclear Physics Cracow operates as a pulsed and/or stationary neutron source. Its experimental set-up for research of time-dependent thermal neutron fields in various media is presented. The electronic control systems for the generator and for data acquisition, necessary to assure the required measurement conditions, have been designed and built by the authors. The new electronic equipment makes it possible to do the measurements with high accuracy and repeatability. The macroscopic absorption cross section for environmental materials, like rocks, borehole and formation fluids, are measured routinely using the pulsed neutron source by two methods elaborated in INP. The pulsed neutron parameters for homogeneous and heterogeneous materials (e. g. containing absorbing centers in a low absorption matrix) can be also measured by the geometrical buckling method on the same experimental set-up. Experiments for materials of variable bulk densities are going on. Other experiments are related to a verification of new theoretical models of thermal neutron scattering in hydeogeneous media. (author)