EU Science Hub

HADES underground laboratory

IRMM operates a laboratory for ultra-sensitive radioactivity measurements inside the 225 m deep underground laboratory HADES, which is operated by EURIDICE and located at the premises of the Belgian Nuclear Research Centre. In HADES, the muon flux (secondary cosmic rays) is a factor of 5000 lower compared to above ground and the flux of protons, neutrons and electrons is reduced to an insignificant level. This reduction of the cosmic ray flux makes the background in gamma-ray spectrometry measurements significantly lower compared to above ground. Therefore it is possible to detect very low amounts of radioactivity, we are talking about levels of some hundred mBq (micro-Becquerel, i.e. a few nuclear disintegrations per day). Twelve specially designed low-background gamma-ray detectors are used for the measurements. The measurements support projects in a wide range of fields, and over 200 projects have been carried out the past 15 years.

IRMM: stories behind the scenes