Simulation of Virtual SANS Spectrometers at IBR-2 Reactor

Abstract

The experience gained in the last 15 years of experimental studies of large-scale structures with the SANS instrument at the IBR-2 pulsed reactor in Dubna shows that some parameters of the spectrometer can be improved. In particular, it concerns reduction of the fast neutron and gamma backgrounds that limit the possibilities of studying weakly scattering objects. Another direction of improvement is to reduce a minimum momentum transfer value Q_min to study objects with larger characteristic dimensions. The paper investigates several configurations of the SANS machine at IBR-2. The Monte Carlo codes are used to calculate the parameters of such virtual instruments. An optimal instrument structure is proposed.