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·Neutron emission rate for an Am-Be neutron source and a Cf neutron source: (unit: s-1) : 1x103-2x107s-1 for Am-Be, 1x103-3x107s-1 for Cf
Neutron emission rate of a radioactive neutron source is calibrated using the AIST graphite pile.
Acceptable activity
Am-Be source: 185 GBq, 111 GBq, 37 GBq, 18.5 GBq, 11.1 GBq, 3.7 GBq
Cf source: 200 MBq, 100 MBq, 40 MBq, 20 MBq, 10 MBq, 3.7 MBq, 3.6 MBq, 2.0 MBq, 1.11 MBq
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·Thermal neutron fluence rate (unit: cm-2s-1) 5x101-104cm-2s-1
Thermal neutrons are produced with an 241Am-Be neutron source (148 GBq) at the center of a graphite pile. The absolute neutron fluence rate distribution in the graphite pile was given by the gold activation method with a 4 pi beta-gamma coicidence system. The thermal neutron spectrum was given by the MCNP4C code. A 3He proportional counter is used as a working standard.
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·24 keV mono-energetic neutron fluence (unit: cm-2) 103-108cm-2
24-keV neutrons are produced by a iron filtered 7Li(p,n)7Be reaction using a proton beam from the 4-MV Pelletron accelerator. Neutron fluence was determined by a 3He proportional counter. A long counter is used as a working standard.
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·144 keV and 565 keV mono-energetic neutron fluence (cm-2) 103-108cm-2
144-keV and 565-keV neutrons are produced by the 7Li(p,n)7Be reaction using a proton beam from the 4-MV Pelletron accelerator. Neutron fluence was determined by a recoil proton proportional counter. A long counter is used as a working standard.
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·2.5 MeV mono-energetic neutron fluence (cm-2) 103-107cm-2
2.5-MeV neutrons are produced by the D(d,n)3He reaction using a deuteron beam from the 300-kV Cockcroft-Walton accelerator. Neutron fluence was determined by a thick radiator detector that is composed of a polyethylene foil with 0.5-mm thick and a silicon surface barrier detector. A long counter is used as a working standard.
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·5.0 MeV mono-energetic neutron fluence (cm-2) 103-108cm-2
5.0-MeV neutrons are produced by the D(d,n)3He reaction using a deuteron beam from the 4-MV Pelletron accelerator. Neutron fluence was determined by a thick radiator detector that is composed of a polyethylene foil with 1-mm thick and a silicon surface barrier detector. A long counter is used as a working standard.
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·8.0 MeV neutron fluence (cm-2) 103-108cm-2
8.0-MeV neutrons are produced by the 9Be(a,n)12C reaction using a helium beam from the 4-MV Pelletron accelerator. Absolute neutron fluence was given by a dE-E Thick radiator detector that is composed of a polyethylene foil with 1-mm thick and two silicon surface barrier detector. A long counter is used as a working standard.
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·14.8 MeV mono-energetic neutron fluence (cm-2) 103-108cm-2
14.8-MeV neutrons are produced by the T(d,n)4He reaction using a deuteron beam from the 300-kV Cockcroft-Walton accelerator. Absolute neutron fluence was given by an associated particl detector with a silicon surface barrier detector. The associated particle detector is also used as a working standard.
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·45 MeV High energy neutron fluence rate (cm-2s-1)
45-MeV neutrons are produced by the 7Li(p,n) reaction using a proton beam from the TIARA AVF cyclotron of the National Institutes for Quantum and Radiological Science and Technology. Neutron fluence was determined by a proton recoil telescope that is composed of a polyethylene radiator, a Si detector and a liquid scintillator. A plastic scintillator on the neutron beam line is used as a working standard.
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·241Am-Be or 252Cf source spectral neutron fluence (cm-2): 103-108cm-2
·241Am-Be or 252Cf source spectral neutron ambient dose equivalent rate (Sv/h)
·241Am-Be or 252Cf source spectral neutron personal dose equivalent rate (Sv/h)
Neutron fluence was determined using the neutron emission rate of the neutron source and inverse square law of the distance between the detection position and the neutron source.
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·D2O moderated 252Cf source spectral neutron fluence (cm-2) : 8.8x102-8.9x107cm-2
·D2O moderated 252Cf source spectral neutron ambient dose equivalent rate (Sv/h)
·D2O moderated 252Cf source spectral neutron personal dose equivalent rate (Sv/h)
Neutron fluence was comfirmed using a 3He proportional counter with a polyethylene moderator. Neutron energy distribution was measured with a Bonner sphere spectrometer.
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