Construction Process with Monte Carlo of a Lead-Moderated ²⁴¹Am-Be System to Simulate the Neutron Spectrum of ²⁵²Cf

Angela Souza Gonçalves; Lunia Coelho de Almeida de Lima; Antônio Carlos Ferreira; Marcelo Marques Martins; Walsan Wagner Pereira

doi:10.15392/2319-0612.2025.2915

Autores/as

Angela Souza Gonçalves Institute of Radioprotection and Dosimetry , Instituto de Radioproteção e Dosimetria
Lunia Coelho de Almeida de Lima IRD , Instituto de Radioproteção e Dosimetria
Antônio Carlos Ferreira IRD , Instituto de Radioproteção e Dosimetria
Marcelo Marques Martins IRD , Instituto de Radioproteção e Dosimetria
Walsan Wagner Pereira IRD , Instituto de Radioproteção e Dosimetria

DOI:

https://doi.org/10.15392/2319-0612.2025.2915

Palabras clave:

Californium, Americium-Beryllium, Monte Carlo Simulation, Neutron Metrology.

Resumen

Over the years, as the use of the radionuclide ²⁵²Cf has expanded across various fields, its availability has decreased, and its cost has risen exponentially, making it the second most expensive material in the world, after antimatter. In contrast, the ²⁴¹Am-Be source is highly accessible, significantly cheaper, and has a long half-life. By employing absorber and moderator materials, neutron fields can be modified. This study presents the Monte Carlo simulation process for developing a lead-based system capable of producing a ²⁵²Cf-like neutron field from a moderated ²⁴¹Am-Be source. To match the 2.13 MeV energy of ²⁵²Cf, a spherical lead geometry with a radius of 12.56 cm was selected. The simulations achieved an average neutron energy of 2.13 ± 0.11 MeV, with conversion coefficients H*(10) and Hp(10;0) differing by only 4–6% from the reference ²⁵²Cf values. The low-cost lead moderator system suits calibration procedures and routine irradiation in neutron metrology laboratories.

Descargas

Los datos de descarga aún no están disponibles.

Referencias

[1] METALARY, DAILY METAL PRICES. Disponível em: . Acesso em: 09 de abril. 2025.

[2] KARELIN, Y.A., GORDEEV, Y.N., KARASEV, V.I. et al., 1997, “Californium-252 Neutron Sources”. Appl. Radiat. Isot., v. 48, n. 10-12, pp. 1563-1566. DOI: https://doi.org/10.1016/S0969-8043(97)00156-5

[3] MARTIN, R.C., KNAUER, J.B., BALO, P.L., 2000. Production, Distribution and Applications of Califormium-252 Neutron Sources Appl. Radiat. Isot. 53, 785-792. DOI: https://doi.org/10.1016/S0969-8043(00)00214-1

[4] IAEA, 2001, Compendium of Neutron Spectra and Detector Responses for Radiation Protection Purposes (Supplement to TRS nº 318) — TRS nº 403, International Atomic Energy Agency, Vienna.

[5] ISO 8529-1 2nd ed., 2021, Reference neutron radiations – Part 1: Characteristics and methods of production, Geneva: ISO.

[6] GONÇALVES, A. S., et al., A feasibility study of a H2O-moderated 252Cf source for metrology. Brazilian Journal of Radiation Sciences, Rio de Janeiro, Brazil, v. 11, n. 1A (Suppl.), p. 1–10, 2023. DOI: 10.15392/2319-0612.2023.2216. DOI: https://doi.org/10.15392/2319-0612.2023.2216

[7] GONÇALVES, A. S., K. C. S. Patrão., W. W. Pereira., A study of a H2O-moderated 241AmBe source for neutron metrology. Brazilian Journal of Radiation Sciences, Rio de Janeiro, Brazil, v. 12, n. 4A (Suppl.), p. e2724, 2025. DOI: 10.15392/2319-0612.2024.2724. DOI: https://doi.org/10.15392/2319-0612.2024.2724

[8] BRIESMEISTER, J. F., 2001. MCNP, A General Monte Carlo N-Particle Transport Code. Los Alamos National Laboratory, Version 4C2, USA.

[9] EXLINE, P. R., 2011. Characterization of Modified Neutron Fields with Americium-Beryllium and Californium-252 Sources. M.Sc. Thesis. Georgia Institute of Technology. USA

[10] MERCK & Co., 2001, The Merck Index – An Encyclopedia of Chemicals, Drugs and Biologicals. 13rd ed. Whitehouse Station, NJ, Merck Research Laboratories.