Download Neutron Spectrum Measured in Aberdeen Tunnel

NEUTRINO2010, XXIV International Conference on Neutrino Physics and
Astrophysics, Athens, GREECE
Contribution ID : 50
Type : not specified
Neutron Spectrum Measured in Aberdeen Tunnel
Underground Laboratory with a Multisphere
Neutron Spectrometer
Neutrons from natural radioactivity and spallation reactions initiated by cosmic ray muons represent a major
source of background for underground neutrino experiments. A set of multisphere neutron spectrometer
was developed. It consisted of 8 Bonner Spheres, made of high-density polyethylene, with diameter from
12.7 cm (5 in) to 30.84 cm (12 in). Lead shells with 1 cm and 2 cm thickness were added to the 15.24 cm (6 in)
sphere to increase the detection efficiency of high-energy neutrons (E > 10 MeV). The response matrices of the
detectors were calculated with Geant4 from 1 eV to 1 GeV. The neutron spectrum inside the Aberdeen Tunnel
Underground Laboratory, with an overburden of ~660 m.w.e., was measured with the neutron spectrometer
which was calibrated with an AmBe source. The neutron spectrum and flux were deduced by unfolding the
measured count rates using a genetic algorithm.
Summary
Primary author(s) : Mr. LIU, Hao (Department of Physics, The University of Hong Kong, Hong Kong)
Co-author(s) : Mr. WONG, C.M. (Department of Physics, The Chinese University of Hong Kong, Hong
Kong); Mr. NGAI, H.Y. (Department of Physics, The University of Hong Kong, Hong Kong); Dr. PUN, J.C.S. (Department of Physics, The University of Hong Kong, Hong Kong); Dr. LEUNG, J.K.C. (Department of Physics, The
University of Hong Kong, Hong Kong); Prof. LUK, K.B. (Department of Physics, University of California, Berkeley,
USA); Mr. KWON, K.K. (Department of Physics, The Chinese University of Hong Kong, Hong Kong); Mr. WONG,
K.K. (Department of Physics, The Chinese University of Hong Kong, Hong Kong); Mr. TONG, K.P. (Department of
Physics, The University of Hong Kong, Hong Kong); Prof. CHU, M.C. (Department of Physics, The Chinese University of Hong Kong, Hong Kong); Mr. KWOK, M.W. (Department of Physics, The Chinese University of Hong Kong,
Hong Kong); Mr. NGAN, S.Y. (Department of Physics, The Chinese University of Hong Kong, Hong Kong); Mr.
KWOK, T. (Department of Physics, The Chinese University of Hong Kong, Hong Kong); Mr. LUK, W.H. (Department of Physics, The Chinese University of Hong Kong, Hong Kong); Ms. LAI, W.Y. (Department of Physics, The
University of Hong Kong, Hong Kong); Mr. CHEN, X.C. (Department of Physics, The Chinese University of Hong
Kong, Hong Kong); Dr. LIN, Y.C. (Department of Physics, The University of Hong Kong, Hong Kong)
Presenter(s) : Mr. LIU, Hao (Department of Physics, The University of Hong Kong, Hong Kong)