The International Axion Observatory (IAXO) is a proposed fourth generation axion helioscope. It aims at a sensitivity much improved with respect to CAST. The conceptual design of the experiment has been finished and a Letter of Intent recently submitted for consideration to the SPS committee of CERN.
One of the technological pillars of the project are ultra low background x-ray detectors based on Micromegas readouts, as developed within T-REX
You can find the IAXO “Letter of Intent” and learn more about IAXO here.
Conceptual design of IAXO