Development of New NiO-doped Silicate Glass for Poly-capillary Neutron Optics

Poly-capillary neutron optics have been used to transport and bend thermal and cold neutrons based on multiple total external reflection from smooth surfaces at small grazing angles. The poly-capillary focusing lens consisting of capillary fibers have been developed and demonstrated. The critical angle and neutron absorption efficiency of the glass used in poly-capillary fibers influence the gain of the focusing lens. The poly-capillary fibers with a larger critical angle and a lower neutron absorption efficiency will achieve a higher gain. NiO was introduced in the glass system to increase the critical angle. Novel NiO-doped silicate glass with a critical angle of 11.31mrad/nm and a neutron absorption of 6.64×10^-4 have been developed and the NiO-doped silicate glass tube with a diameter of 30mm and a length of 300mm has been manufactured.