Abstract
A micro focusing Small Angle Neutron Scattering (mf-SANS) instrument is planned for compact accelerator based neutron source project to analyze the internal structure of material in 1-100 nm scale. As the key component, the ellipsoidal neutron mirror strongly affects the focusing performance of mf-SANS instrument. To fabricate the neutron mirror, this paper presents a new manufacturing process chain by following the steps of fast milling and precision cutting of aluminium, electroless nickel plating, ultra-precision cutting by diamond tools, super-smooth polishing and super mirror coating to generate the mirror with high form accuracy and good surface roughness time-efficiently. As a preliminary test of the proposed process chain, a workpiece with flat surface made of electroless nickel plating on aluminium is adopted and machined by ultra-precision cutting and polishing. The surface roughness is reduced to under 1 rms. According to the experiment results of reflectometry, the neutron beam can be totally reflected with high intensity and little scattering.
