Gamma-ray flux in the Fréjus underground laboratory measured with NaI detector
Nucl. Instr. and Meth. in Phys. Res. A482 (2002) pp. 832-839
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.
Cite article as:
. NEMO Collaboration, "Gamma-ray flux in the Fréjus underground laboratory measured with NaI detector", Nucl. Instr. and Meth. in Phys. Res. A482 (2002) pp. 832-839 (2002)