Boin, M.; Wimpory, R.C.; Hilger, A.; Kardjilov, N.; Zhang, S.Y.; Strobl, M.: Monte Carlo simulations for the analysis of texture and strain measured with Bragg edge neutron transmission. Journal of Physics : Conference Series 340 (2012), p. 012022/1-12
10.1088/1742-6596/340/1/012022

Abstract:
The transmission spectrum of cold and thermal neutrons displays sudden intensity changes, known as Bragg edges, whose appearance is connected to the crystallographic structure of the investigated sample. However, many difficulties in interpreting and understanding the detected signal exist, in particular when results are evaluated quantitatively. We measured strain and texture properties of different samples utilizing the Bragg edge method on the CONRAD and VSANS instruments at Helmholtz Centre Berlin as well as on ENGIN-X at ISIS, UK. The different results will be compared and validated with conventional diffraction measurements and theoretical considerations. According to this, a Bragg edge neutron transmission simulation was developed to include instrument effects together with sample characteristics. Therefore, a neutron ray-tracing simulation package was applied to emulate the employed instruments in combination with the Bragg edge transmission technique. A new sample module has been created to realize energy-dependent transmission simulations based on neutron cross sections calculations. Towards the analysis of the conducted experiments the virtual sample features the expected strain and texture parameters. The results of the simulation are in good agreement with the experiments and will be discussed with regard to the prospects and limitations of this measurement method and the utilized instruments.