Focusing neutrons with tapered capillary optics

Abstract

A monolithic polycapillary focusing optic for polychromatic neutron diffraction applications Rev.Neutron focusing using capillary optics and its applications to elemental analysis AIP Conf.The transmission characteristics of radiation through hollow tapered capillaries may be described by expressions derived for straight capillaries but with a reduced critical angle. The size of the focused beam for recent transmission measurements through a tapered polycapillary focusing optic performed at various different wavelengths gives a measure of the reduced critical angle. We derive the transmission characteristics of the focusing lens from the measured data and compare these with the analytic results. A similar comparison is made for a polychromatic incident beam.