Next-generation high transmission neutron optical devices utilizing micro-machined structures

Abstract

Neutrons have emerged as a unique probe at the forefront of modern material science, unrivaled in their penetrating abilities. A major challenge stems from the fact that neutron optical devices are limited to refractive indices on the order of n ≈ 1 ± 10 −5 . By exploiting advances in precision manufacturing, we have designed and constructed a micro-meter period triangular grating with a high aspect ratio of 14.3. The manufacturing quality is demonstrated with white-light interferometric data and microscope imaging. Neutron scattering experiment results are presented, showing agreement to refraction modelling. The capabilities of neutron Fresnel lenses based on this design are contrasted to existing neutron focusing techniques and the path separation of a prism-based neutron interferometer is estimated.