Obelix, a new low-background HPGe at Modane Underground Laboratory
- Laboratoire Souterrain de Modane, CNRS-CEA, 1125 route de Bardonnèche, 73500 Modane (France)
- JINR, Joint Institute for Nuclear Research, 141980, Dubna (Russian Federation)
- IEAP, Czech Techincal University in Prague, 12800 Prague (Czech Republic)
An ultra-low background coaxial HPGe detector for gamma-ray spectrometry with a relative efficiency of 160%, corresponding to a 600 cm{sup 3} Ge crystal, was installed at the Laboratoire Souterrain de Modane, France (4800 m.w.e). To reduce the instrinsic detector background, all parts involved in the detector cryostat were selected for their low radioactivity contamination. A shielding, composed of an inner layer of roman lead and an external layer of regular lead was installed, together with a system to reduce the Rn level inside the sample chamber. The shielding was designed to allow the measurement of Marinelli-shaped samples. We present the constructional details which lead to a remarkable low detector background of 73 cts/kg·d in [40, 3000] keV. Measured samples showed that sensitivities about 100 μBq/kg in {sup 226}Ra and {sup 228}Th are reached for samples of some kg and 30 days of lifetime.
- OSTI ID:
- 22488727
- Journal Information:
- AIP Conference Proceedings, Vol. 1672, Issue 1; Conference: LRT 2015: 5. international workshop in low radioactivity techniques, Seattle, WA (United States), 18-20 Mar 2015; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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