2009: The Sandwich spectrometer for ultra low-level γ-ray spectrometry

Applied Radiation and Isotopes
Volume 67, Issue 5, May 2009, Pages 731-735

J.S. Elisabeth Wieslander a, d, Mikael Hult a, Joël Gasparro a, Gerd Marissens a, Marcin Misiaszek b and Werner Preusse a, c

a) EC-JRC-IRMM, Institute for Reference Materials and Measurements, Retieseweg 111, B-2440 Geel, Belgium
b) M. Smoluchowski Institute of Physics, Jagiellonian University, ul. Reymonta 4, 30-059 Krakow, Poland
c) Saxon State Laboratories for Environmental Radioactivity, Dresdner Street 183, D-09131 Chemnitz, Germany
d) Department of Physics, P.O. Box 35 (YFL), FIN-40014 University of Jyväskylä, Finland



The technical details and performance of the newly developed Sandwich spectrometer for ultra low-level γ-ray spectrometry are presented. The spectrometer, which consists of two HPGe detectors, an active muon shield and a lead/copper shield with a convenient and rapid opening mechanism, is located in an underground laboratory at a depth of 500 m water equivalent. The data is collected in list mode, which enables off-line data analysis to identify muon-induced events and possible Ge detector crosstalk due to Compton scattering. The background count-rate from 40 to 2700 keV normalised to the mass of the Ge crystals is 220 day−1 kg−1