The Effect of Straight and Elliptic Neutron Guides with Nickel Coating on the Neutron Intensity Distribution

Neutron focusing with specific energy and intensity distribution from neutron source plays an important role in various applications. In this paper, the effect of straight and elliptical guide systems for focusing on the neutron intensity on the target has been investigated for a neutron source as a Maxwell distribution in the range of wavelength from 0.5 to 5 angstroms. The simulations were performed using the Monte Carlo simulation code McStas and the effects of different parameters of straight and elliptical neutron guides on the neutrons intensity have been obtained. Then, the results of straight and elliptical guide systems are also compared. Studying the role of the straight and elliptical guide's length shows that increasing the guide length, the output intensity increases and after an optimal length, it decreases. The results show that for the straight guide, optimization of the distance between the source to the guide has the greatest effect on the intensity of the output neutrons versus wavelength, while for the elliptic guide, optimization of the source radius has the greatest effect. Finally, the results show that the performance of the elliptical guide is better than the straight guide.