Small-angle neutron scattering diffractometer at Dhruva reactor

A small-angle neutron scattering (SANS) diffractometer has been recently installed at the guide hall of the Dhruva reactor at Trombay. The diffractometer uses a BeO filter as the monochromator. The mean wavelength of the incident neutron beam is 5. A, with a wavelength resolution of approximately 15%. The angular divergence of the incident beam is ± 0.5 deg and the beam size at the sample position is 1.5 cm x 1.0 cm. The scattered neutrons are detected in an angular range of 1-15 deg using a linear 3He position-sensitive gas detector. The Q range of the diffractometer is 0.018-0.32 A-1. The diffractometer is well suited for the study of a wide variety of systems having characteristic dimensions between 10 and 150 A. This paper gives the design features and the resolution function of SANS diffractometer. (author)