X-ray focussing mirrors
Date: 02 February 2016
Satellite: Hitomi
Depicts: X-ray focussing mirrors (schematic)
Copyright: JAXA
This illustration shows how the mirror systems employed in X-ray telescopes work.
In order to be reflected (rather than absorbed) by a mirror, X-rays must barely graze its surface, hitting it at a very small angle: 1° or even less. For this reason, X-ray telescopes employ hundreds of conical shells coated in reflecting material, nestled into one another to make the total reflecting surface as large as possible.
The X-ray telescopes on the Hitomi satellite consist of conically approximated Wolter I grazing incidence optics. Hitomi (known as ASTRO-H prior to launch) is a high-energy astrophysics space observatory, developed by the Japan Aerospace Exploration Agency (JAXA) in collaboration with institutions in Japan, the US, Canada, and Europe.
