Design and fabrication of a 1.2 meter long internally cooled silicon x-ray mirror for APS

This paper describes the specifications, design, and fabrication of a 1.2 meter long ultra high vacuum (LTHV) silicon mirror for use as the first optical element on an x-ray beamline at APS. The mirror, which is 1200 mm x 90 mm x 120 mm in size, intercepts the incident x-ray beam at 0.15 degrees. The thermal power incident on the mirror is 1.2 kW with a peak heat flux of 0.38 W/mm(2). The heat is removed by flowing water through a set of channels configured in the face plate of the mirror. Various aspects of this mirror, including its purpose, utility, expected thermal and structural performance, cooling design, UHV provision, support and mounting, surface figure and finish, bonding of the cooling conduits, and other manufacturing steps are discussed.