Testing and modelling of the SVOM MXT narrow field lobster eye telescope optic

摘要

The Space-based multi-band astronomical Variable Objects Monitor (SVOM) is a French-Chinese space mission to be launched in 2021 with the goal of studying gamma-ray bursts, the most powerful stellar explosions in the Universe. The MicroChannel X-ray Telescope (MXT) on-board SVOM, is an X-ray focusing telescope with a detector-limited field of view of ～1 square°, working in the 0.2-10 keV energy band. The MXT is a narrow-field-optimised lobster eye telescope, designed to promptly detect and accurately locate gamma-ray burst afterglows. The breadboard MXT optic comprises of an array of square pore micro pore optics (MPOs) which are slumped to a spherical radius of 2 m giving a focal length of 1 m and an intrinsic field of view of ～6°. We present details of the baseline design and results from the ongoing X-ray tests of the breadboard and structural thermal model MPOs performed at the University of Leicester and at Panter. In addition, we present details of modelling and analysis which reveals the factors that limit the angular resolution, characteristics of the point spread function and the efficiency and collecting area of the currently available MPOs.