A high performance neutron powder diffractometer at 3 MW Triga Mark-II research reactor in Bangladesh

• Main Authors: Kamal, I., Yunus, S. M., Datta, T. K., Zakaria, A. K. M., Das, A. K., Aktar, S., Hossain, S., Berliner, R., Yelon, W. B.
• Format: Conference Proceeding
• Language: English
• Subjects: BEAMS; CERAMICS; Ceramics industry; Collimation; COLLIMATORS; Crystal structure; Data buses; Dependence; Design optimization; FILTERS; High density polyethylenes; High temperature; INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; MAGNETIC MATERIALS; Magnetic properties; MONOCHROMATORS; MONOCRYSTALS; NEUTRON DIFFRACTION; Neutron flux; Neutron scattering; Neutrons; NUCLEAR INSTRUMENT MODULES; Polyethylenes; Position sensing; POSITION SENSITIVE DETECTORS; POWDERS; PROPORTIONAL COUNTERS; RESEARCH REACTORS; RESOLUTION; SAPPHIRE; Sensors; SILICON; Single crystals; STEELS; THICKNESS; TRIGA TYPE REACTORS
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/1.4958454

A high performance neutron diffractometer called Savar Neutron Diffractometer (SAND) was built and installed at radial beam port-2 of TRIGA Mark II research reactor at AERE, Savar, Dhaka, Bangladesh. Structural studies of materials are being done by this technique to characterize materials crystallograpohically and magnetically. The micro-structural information obtainable by neutron scattering method is very essential for determining its technological applications. This technique is unique for understanding the magnetic behavior in magnetic materials. Ceramic, steel, electronic and electric industries can be benefited from this facility for improving their products and fabrication process. This instrument consists of a Popovicimonochromator with a large linear position sensitive detector array. The monochromator consists of nine blades of perfect single crystal of silicon with 6mm thickness each. The monochromator design was optimized to provide maximum flux on 3mm diameter cylindrical sample with a relatively flat angular dependence of resolution. Five different wave lengths can be selected by orienting the crystal at various angles. A sapphire filter was used before the primary collimator to minimize the first neutron. The detector assembly is composed of 15 linear position sensitive proportional counters placed at either 1.1 m or 1.6 m from the sample position and enclosed in a air pad supported high density polythene shield. Position sensing is obtained by charge division using 1-wide NIM position encoding modules (PEM). The PEMs communicate with the host computer via USB. The detector when placed at 1.1 m, subtends 30˚ (2θ) at each step and covers 120˚ in 4 steps. When the detector is placed at 1.6 m it subtends 20˚ at each step and covers 120˚ in 6 steps. The instrument supports both low and high temperature sample environment. The instrument supports both low and high temperature sample environment. The diffractometer is a state-of-the art technology for diffraction study in our country.