The design of a multisource americium–beryllium (Am–Be) neutron irradiation facility using MCNP for the neutronic performance calculation

• Published in: Applied radiation and isotopes Vol. 90; pp. 192 - 196
• Main Authors: Sogbadji, R.B.M., Abrefah, R.G., Nyarko, B.J.B., Akaho, E.H.K., Odoi, H.C., Attakorah-Birinkorang, S.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2014
• Subjects: Americium‐Beryllium source; Multi-source irradiation; Neutron flux; Thermal Neutrons; Ghana; Neutron flux; Americium‐Beryllium source; Multi-source irradiation; Thermal Neutrons
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2014.03.017

The americium–beryllium neutron irradiation facility at the National Nuclear Research Institute (NNRI), Ghana, was re-designed with four 20Ci sources using Monte Carlo N-Particle (MCNP) code to investigate the maximum amount of flux that is produced by the combined sources. The results were compared with a single source Am–Be irradiation facility. The main objective was to enable us to harness the maximum amount of flux for the optimization of neutron activation analysis and to enable smaller sample sized samples to be irradiated. Using MCNP for the design construction and neutronic performance calculation, it was realized that the single-source Am–Be design produced a thermal neutron flux of (1.8±0.0007)×106n/cm2s and the four-source Am–Be design produced a thermal neutron flux of (5.4±0.0007)×106n/cm2s which is a factor of 3.5 fold increase compared to the single-source Am–Be design. The criticality effective, keff, of the single-source and the four-source Am–Be designs were found to be 0.00115±0.0008 and 0.00143±0.0008, respectively. •Thermal neutron flux for single Am–Be source varies at different position.•The proposed channel has higher neutron flux than the existing channels being used.•Multi source Am–Be was design has neutron flux more than three folds that of the single source.•NAA and PGNAA were experiment discovered to be feasible for this new design.•Research institutes that cannot purchase research reactor could adopt the Multi source Am–Be design.