Designing and Constraints in the Development of Focusing Small Angle Neutron Scattering Beamline at a Small Research TRIGA Reactor

A Monte-Carlo ray tracing simulation together with an analytical approach were carried out to understand flux characteristics and performance of the small angle neutron scattering (SANS) instrument at the Malaysian Nuclear Agency's 1 MW TRIGA reactor. The low flux and limited Q range of the instrument can be further improved by developing the instrument as focusing SANS. The use of misaligned HOPGs as monochromator can increase the △λ/λ thereby increasing the flux at sample position. In this case, a much tighter collimation can be used to get better Q(subscript min). This paper explains a misaligned HOPGs design concept, constraints and possible approaches to achieve a higher flux and the modification needs to establish a focusing SANS at small research reactor.