Author/Authors :
Ohsumi، نويسنده , , H. and Gurriar?n، نويسنده , , R. and Hubert، نويسنده , , Ph. and Arnold، نويسنده , , R. and Augier، نويسنده , , C. and Baker، نويسنده , , J. and Barabash، نويسنده , , A. and Bing، نويسنده , , O. and Brudanin، نويسنده , , V. and Caffrey، نويسنده , , A.J. and Campagne، نويسنده , , J.E. and Caurier، نويسنده , , E. and Dassie، نويسنده , , D. and Egorov، نويسنده , , V. and Errahmane، نويسنده , , K. and Eschbach، نويسنده , , R. a، نويسنده ,
Abstract :
The γ-ray flux in the Fréjus underground laboratory has been studied using an NaI detector surrounded by different diagonostic shields. Below 4 MeV, the spectrum is dominated by radioactivities in the surrounding materials and rocks. Between 4 and 6 MeV, the shape of the spectrum is well explained by U, Th and daughters, which are internal contaminations in the NaI crystal. Between 6 and 10 MeV, the γ-ray flux is strongly correlated with neutron captures in the surrounding materials. Finally, the γ-ray flux above 10 MeV falls off and is related to the very weak cosmic muon flux via muon bremsstrahlung.
Keywords :
Neutron capture ?-ray , Background , Double beta decay , Underground laboratory , ?-Ray flux , NaI Detector
