The hypothetical particles known as axions could be an important component of dark matter. The aim of the proposed International Axion Observatory (IAXO) is to search for axions with a signal-to-noise ratio some 105 better than the pioneering CERN Axion Solar Telescope (CAST). Such an improvement is possible only by building a large magnet, together with optics and detectors that optimize the experiment’s capabilities. The central component of IAXO would be a superconducting toroid magnet, while the detector would rely on a high magnetic field distributed over a large volume to convert solar axions to detectable X-ray photons.
Read more: "IAXO: the International Axion Observatory" – CERN Courier