Neutron Optics: Characterization and Use of Neutron Waveguides

Neutron optics exploits the similarities between the quantum-mechanical description of neutron propagation and scattering and the equivalent equations of light propagation used in classical optics.One of its most exciting possibilities relies on neutron waveguiding in a similar way an optical fibre, or a waveguide, does with light.This possibility was proposed by De Wames and Sinha, in 1973 and experimentally demonstrated by Kumakhov, in 1992.This paper reviews the work in the author's PhD thesis, where it has been proposed an original rigorous mathematical characterization of how a thermal neutron beam impinging a waveguide extincts, gives rise to propagation modes and propagates (including its escape via tunnelling effect).This new mathematical characterization led to the development of an original efficient algorithm never implemented before for simulation including holography.The final goal is to identify critical parameters to improve the design of waveguiding devices.The main challenge is that, when one simulates waveguides with transverse dimensions (aperture) orders of magnitude higher than the neutron wavelength, it involves complex integral equations with a huge volume of data to handle and compute.