Optics and Precision Engineering, Volume. 29, Issue 9, 2075(2021)
Focusing performance evaluation of ellipsoidal neutron-focusing mirror for small-angle neutron scattering
Neutrons are widely used in the microstructure inspection of materials and biological samples owing to their strong penetrating power. However, the intensity of the neutron beam is weaker than that of X-rays. A neutron-focusing mirror is usually employed to efficiently utilize a neutron beam. In this study, an ellipsoidal neutron-focusing mirror using a metal substrate was developed based on the high-performance manufacturing concept. Experiments on the focusing and small-angle neutron scattering (SANS) of the mirror were conducted. The results show that the maximum intensity of the focused neutron beam is 103 of the diffuse scattering intensities. A circular focusing spot with a size almost equivalent to that of one of the upstream pinholes was created. The experiment of focus was conducted away from the best focal plane. The beam profiles at several mirror-center-to-detector distances were obtained and the FWHM values of the beam profiles were in good agreement with the theoretical estimations based on the geometric optics. The wavelength distributions, such as the direct beam and the reflected beam were analyzed. The reflectivity of the neutron focusing mirror reaches 60%, and the peak intensity exceeded 1 000 counts/pixel (0.1 mm×0.1 mm). Moreover, a preliminary result for SANS using a standard sample made of porous silica (MCM-41) was reported. Studies have shown that the ellipsoidal neutron-focusing mirror has satisfactory focusing performance, which is sufficient for small-angle neutron scattering research.
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Jiang GUO, Lin-guang LI. Focusing performance evaluation of ellipsoidal neutron-focusing mirror for small-angle neutron scattering[J]. Optics and Precision Engineering, 2021, 29(9): 2075
Category: Modern Applied Optics
Received: Jan. 28, 2021
Accepted: --
Published Online: Nov. 22, 2021
The Author Email: GUO Jiang (guojiang@dlut.edu.cn)