Fig 1.
Cross sections for different nuclear reactions between neutrons and 12C atoms.
Fig 2.
Elastic scattering cross section for hydrogen.
Fig 3.
Mean free path for neutrons in polyethylene as a function of the neutron energy.
Fig 4.
Proton range in PE as a function of the proton energy (obtained using SRIM).
Fig 5.
Geometry models and consideration of neutrons beam direction.
(a) Geometry of interactions in the PE layer. (b) Schematic diagram showing the neutron beam direction.
Fig 6.
Penetration fraction of neutrons as a function of the PE layer thickness with energy as a parameter.
(a) Energy range from 100 keV to 2 MeV. (b) Energy range from 3 to 10 MeV.
Fig 7.
Efficiency of proton production as a function of the PE layer thickness with energy as a parameter (energy range from 2 to 10 MeV).
Fig 8.
Distribution of protons as a function of the proton energy with the thickness of the PE layer as a parameter (in cm).
(a) For incident neutron energy of 0.5 MeV; (b) for incident neutron energy of 1 MeV; (c) for incident neutron energy of 5 MeV; (d) for incident neutron energy of 10 MeV.
Fig 9.
Distribution of protons as a function of the angle with the thickness of the PE layer as a parameter (in cm).
(a) For incident neutron energy of 0.5 MeV; (b) for incident neutron energy of 1 MeV; (c) for incident neutron energy of 5 MeV; (d) for incident neutron energy of 10 MeV.
Fig 10.
Comparison between the energy distributions of protons exiting from the opposite side of a PE layer obtained using the FLUKA code and our present code.
(a) FLUKA results for 1 MeV neutrons impinging PE layer; (b) FLUKA results for 10 MeV neutrons; (c) Results from our computer code for 1 MeV neutrons; (d) Results from our computer code for 10 MeV neutrons.