A single mirror foil of XRISM’s XMA

An engineer holding one mirror foil segment of the X-ray Mirror Assembly (XMA). XRISM has two XMA’s, each consisting of a total of 1624 foil segments. X-rays are not measurable by classical telescope mirrors since they pass through them. To measure X-rays, XRISM will use a cylindrical construction of thin foils with small grazing angles. The collecting area of the X-ray telescope is increased by adding many layers of those foils. Each of XRISM’s mirror assembly focuses X-rays onto a scientific instrument 5.6 metres away.