New solid state lens for reflective neutron focusing

We have simulated, built and tested a neutron solid state lens based on a modified bender model. The device is 140 mm long and has a focus at a distance of 31 mm behind the end of the lens. It is made of two stacks of 150 μm thick silicon wafers in an aluminum bender with a 20×30 mm2 entrance window. The wafers are coated with m=2Ni-Ti supermirrors and the lens can thus accept the full divergence of a guide with the same wall coating. Measurements were performed with neutrons of wavelength 0.5 nm at the HZB. They showed in the focal line a FWHM of 2.4 mm and a maximum intensity gain of a factor 5.6 when compared to the intensity at the same position without the lens.