The Mercury Imaging X-ray Spectrometer: optics design and characterisation

We report progress in the design, theoretical modeling and experimental characterisation of microchannel plate (MCP) X-ray optics for the BepiColombo Mercury Imaging X-ray Spectrometer (MIXS). We show that MCP optics technology allows the design of a highly capable imaging telescope with 1 m focal length, a 1° field of view and approximately 50 cm2 of on-axis effective area at 1 keV. Of a total instrument mass budget 7.3 kg, less than 2.3 kg is allocated to the optics assemblies, telescope tubes, support structures and the electron diverters (used to deflect electrons from the focal plane). The instrument science goals require an imaging resolution of 9 arcminutes, with a design goal of 2 arcminutes. Recent experimental data, taken from individual optic elements is presented to show that MCP quality is in good agreement with the error budgets assumed in theoretical calculations of performance.