Photon dose mixed in monoenergetic neutron calibration fields using Li(p,n)Be reaction

Tanimura, Yoshihiko   ; Tsutsumi, Masahiro; Yoshizawa, Michio  

Mono-energetic neutron calibration fields have been established in the energy range from 8 keV to 19 MeV using an accelerator at FRS. In the 144, 250 and 565 keV fields, mono-energetic neutrons are produced by bombarding a LiF target with accelerated protons in order to cause Li(p,n)Be reactions. Photons mixed in these neutron fields, which are produced by other nuclear reactions, can affect the calibration results. These mixed photon dose should be evaluated. In this paper the photons produced by the nuclear reactions between neutrons and target, its supporting materials and the constructional materials of the irradiation room such as the walls, floor and ceiling. were calculated using the MCNP-ANT code. Then the ambient dose equivalent H*(10) of the photons were evaluated and compared with that of the mono-energetic neutrons.