International Conference on Research Reactors:
Safe Management and Effective Utilization

14-18 November 2011, Rabat, Morocco

Neutron Diffraction Patterns Measured with a High-Resolution Powder Diffractometer Installed on a Low-Flux Reactor

V.L. Mazzocchi1, C.B.R. Parente1, J. Mestnik-Filho1, Y.P. Mascarenhas2
1) Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/SP), São Paulo, Brazil
2) Instituto de Física de São Carlos (IFSCAR-USP), São Carlos, Brazil


A powder diffractometer has been recently installed on the IEA-R1 reactor at IPEN-CNEN/SP. IEA-R1 is a light-water open-pool research reactor. At present it operates at 4.5 MW thermal with the possible maximum power of 5 MW. At 4.5 MW the in-core flux is ca. 7×1013 cm-2s-1. In spite of this low flux, installation of both a position-sensitive detector (PSD) and a double-bent silicon monochromator has turned possible to design the new instrument as a high-resolution powder diffractometer. In this work, we present results of the application of the Rietveld method to several neutron powder diffraction patterns. The diffraction patterns were measured in the new instrument with samples of compounds having different structures in order to evaluate the main characteristics of the instrument.

Paper   Presentation