title: Estimation of (41)Ar production in 0.1-1.1.0-GeV proton accelerator vaults using FLUKA Monte Carlo code.
abstract: The FLUKA Monte Carlo simulations are carried out to estimate the (41)Ar concentration inside accelerator vaults of various sizes when proton beams of energy 0.1-1.0 GeV are incident on thick copper and lead targets. Generally (41)Ar concentration is estimated using an empirical formula suggested in the NCRP 144, which assumes the activation is caused only by thermal neutrons alone. It is found that while the analytical and Monte Carlo techniques give similar results for the thermal neutron fluence inside the vault, the (41)Ar concentration is under-predicted by the empirical formula. It is also found that the thermal neutrons contribute ∼41 % to the total (41)Ar production while 56 % production is caused by neutrons between 0.025 and 1 eV. A modified factor is suggested for the use in the empirical expression to estimate the (41)Ar activity 0.1-1.0-GeV proton accelerator enclosures.
authors.affiliation: Health Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors.forename: K
authors.initials: K
authors.lastname: Biju
authors.forename: C
authors.initials: C
authors.lastname: Sunil
authors.forename: P K
authors.initials: PK
authors.lastname: Sarkar
mesh_terms: D001128:Argon / Q000032:analysis*; D003198:Computer Simulation; D006801:Humans; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009502:Neutrons; D010315:Particle Accelerators; D017785:Photons; D011522:Protons; D011829:Radiation Dosage; D011835:Radiation Protection
chemical_list: D011522:Protons; D001128:Argon