Underground Gamma-Ray Spectrometry

Mikael Hult,a* Werner Preußea,b, Joël Gasparroa and Matthias Köhlerc

aEC-JRC-IRMM (Institute for Reference Materials and Measurements), Isotope Measurements Unit, Retieseweg 111, 2440 Geel, Belgium. mikael.hult@cec.eu.int
bSaxon State Laboratories for Environmental Radioactivity, Dresdner Str. 183, D-09131 Chemnitz, Germany
cVerein für Kernverfahrenstechnik und Analytik Rossendorf (VKTA), PF 510119, D‑01314 Dresden, Germany

Gamma-ray spectrometry using high purity Ge detectors has made significant advances in recent years because large crystals have become readily available and the importance of very radiopure materials in the construction of detectors has been understood. The combination of these improvements has made it possible to decrease detection limits in special low-background counting systems. Gamma-ray spectrometry systems located underground are particularly improved by the new developments. This paper deals with the current state-of-the art of underground gamma-ray spectrometry as well as providing examples of new applications of underground gamma-ray spectrometry that were made possible due to the advances in detectors and technique.

Key words: gamma-ray, spectrometry, underground, HPGe, cosmic rays, radioactivity