アイテム詳細

要旨

An X-ray collimator, or baffle, can be installed in the X-ray optics of an X-ray telescope. This component is placed in front of an X-ray mirror to protect the mirror from severe in-orbit thermal environment or to limit the mirror’s field of view. Although the latter may be a disadvantage in the viewpoint of observational performance, the collimation of incident X-rays allows us to block X-rays with large off-axis angles. Thus, the mount of the X-ray collimator results in the reduction of an extended ghost image in the detector field of view that is created by the X-rays, called stray light, with abnormal paths inside the X-ray mirror. The contamination of the stray light hampers both imaging and spectroscopic observations of dim X-ray emission from a spatially extended source or a faint point source. The improvement of the angular resolution and the effective area is intensively pursued for the next-generation X-ray optics. In parallel, it is a vital issue to reduce the stray light as low as possible to fully achieve the expected performance of these future X-ray optics.