Silicon optics for wide field x-ray imaging

Abstract

ABSTRACT Silicon pore optics (SPO) 1 were originally designed to provide very large collecting areas combined with goodangular resolution in narrow “eld X-ray telescopes. We describe modi“cations to the geometry and manufactureof SPO to facilitate wide “eld X-ray imaging applications. Modest changes can greatly improve the vignettingfunction and o-axis angular resolution of SPO in the Wolter I geometry. Recon“guring SPO to form Kirkpatrick-Baez stacks in the Schmidt geometry can provide very large “elds of view with high angular resolution and largecollecting area.Keywords: X-ray optics for astronomy 1. INTRODUCTION Silicon Pore Optics (SPO) technology was “rst introduced by Beijersbergen et al. (2004) 1 andproposedfortheESA XEUS 2 mission in 2005. SPO were subsequently used as the baseline optics for the International X-rayObservatory ( IXO ) 3 in 2010 and most recently have been proposed for the ESA Athena+ 4 mission concept (2013).SPO utilises commercially available Si wafers which have surface “gure and roughness quality ideally suited toX-ray optics applications. The technology has now been under development by ESA and Cosine MeasurementSystems ( http://cosine.nl ) for over a decade.The way in which SPO are manufactured is illustrated in Figure 1. The wafers are diced into rectangles