H.R. Vega-Carrilloª , b, E. Manzanares Acuñaª, J.M. Ortiz Rodríguezª , b, and T. Arteaga Arteagaª ,c
Unidades Académicas:
ª Estudios Nucleares,
b Ing. Eléctrica, Universidad Autónoma de Zacatecas, Apartado Postal 336, 98000 Zacatecas, Zac. México, e-mail: fermineutron@yahoo.com
c Envases de Zacatecas, SA de CV, Parque Industrial de Calera de Víctor Rosales, Zac. México
Recibido el 2 de marzo de 2006 ]]> Aceptado el 18 de agosto de 2006
Abstract
One hundred thirty lethargy neutron spectra in 60 energy groups were converted to energy spectra and re-binned to 31 energy groups. Original spectra were taken form the compilation published by the IAEA and covers neutron spectra from isotopic neutron sources, nuclear reactors, medical and physical application accelerators, cosmic rays, etc. The 31 energy groups were taken from the BUNKIUT unfolding code, which is utilized to obtain the neutron spectrum from a multisphere neutron spectrometer. Re-binned spectra were utilized to calculate the ambient, personal and effective doses covering 13 types of doses. This calculation was carried out through the ICRP74 dose-to-fluence conversion coefficients. This procedure was performed using Monte Carlo methods using the MCNP 4C code. Two experiments were carried out to obtain, with a Bonner sphere spectrometer, the BUNKIUT code and the UTA4 response matrix, the neutron spectra of 252Cf and 252Cf/ D2O. For both sources and at the same locations the equivalent ambient dose were measured using a rem meter. Measured H*(10) and neutron spectra were compared with those obtained in the Monte Carlo calculations.
Keywords: Neutron spectrometry; dose; Monte Carlo.
Resumen
Ciento treinta espectros por unidad de letargia definidos en 60 grupos de energía se convirtieron en espectros por unidad de energía y se re-estructuraron a 31 grupos de energía. Los espectros originales se tomaron de la colección publicada por el OIEA y comprenden espectros producidos por fuentes isotópicas de neutrones, reactores nucleares, aceleradores de uso médico y de investigación en física, rayos cósmicos, etc. Los 31 grupos de energía se tomaron del código de reconstrucción de espectros BUNKIUT que se utiliza para obtener los espectros de neutrones a partir de las tasas de conteo de un espectrómetro de esferas de Bonner. Los espectros re-estructurados se utilizaron para calcular 13 dosis que incluyen la dosis equivalente ambiental, la dosis equivalente personal y la dosis efectiva. Este cálculo se realizó utilizando los coeficientes de conversion de fluencia a dosis del ICRP74. Los cálculos se realizaron utilizando métodos Monte Carlo mediante el código MCNP 4C. Mediante el uso de un espectrómetro de esferas de Bonner, el código BUNKIUT y la matriz de respuesta UTA4 se realizaron dos experimentos donde se determinaron los espectros de dos fuentes de neutrones: 252Cf y 252Cf/D2O. Además de la determinación de los espectros de neutrones se midió el equivalente de dosis ambiental utilizando un dosímetro moderado de neutrones. Los valores de H*(10) y los espectros de neutrones se compararon con los espectros y las dosis obtenidas con los cálculos Monte Carlo.
Descriptores: Espectrometría de neutrones; dosis; Monte Carlo.
]]> PACS: 29.30.Hs; 87.58.Sp; 87.53.Wz
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Acknowledgments
This work was partially supported by CONACyT (México) under contract SEP-2004-C01-46893.
References
1. J.C. McDonald, B.R.L. Siebert, and W.G. Alberts, Physics Research A 476 (2002) 347. [ Links ]
2. D.J. Thomas, Radiation Protection Dosimetry 110 (2004) 141. [ Links ]
3. R.H. Olsher et al., Health Physics 79 (2000) 170. [ Links ]
4. B. Wiegel and A. V. Alevra, Physics Research A 476 (2002) 36. [ Links ]
5. R.H. Olsher et al., Health Physics 86 (2004) 603. [ Links ]
6. J. Saegusa et al., Physics Research A 516 (2004) 193. [ Links ]
7. J.L. Muñiz et al., Radiation Protection Dosimetry 110 (2004) 243. [ Links ]
8. M. Luszik-Bhadra, M. Reginato and V. Lacoste, Radiation Protection Dosimetry 110 (2004) 237. [ Links ]
9. H.R. Vega-Carrillo, E. Manzanares-Acuña, V.M. Hernández-Dávila, and G.A. Mercado Sánchez, Rev. Mex. Fís. 51 (2005) 47. [ Links ]
10. D.T. Bartlett, J.-L. Chartier, M. Matzke, A. Rimper, and D.J. Thomas, Radiation Protection Dosimetry 107 (2003) 23. [ Links ]
11. ICRP, 1990 Recommendations of the ICRP, Publication 60, Annals of the ICRP 21 (1-3), International Commission on Radiological Protection (Pergamon Press, New York, 1991). [ Links ]
12. ICRU, Quantities and Units in Radiation Protection Dosimetry, ICRU Report 51, International Commission on Radiation Units and Measurements (Bethesda, Maryland, 1993). [ Links ]
13. R.L. Bramblett, R.I. Ewing, and T.W. Bonner, Nuclear Instruments and Methods 9 (1960) 1. [ Links ]
14. H.R. Vega-Carrillo and M.P. Iñiguez de la Torre, Physics Research A 476 (2002) 270. [ Links ]
15. H.R. Vega-Carrillo et al., Radiation Measurements 41 (2006) 425. [ Links ]
16. H.R. Vega-Carrillo et al., Artificial neural networks in neutron dosimetry. Radiation Protection Dosimetry. (in press. doi:10.1093/rpd/nci354). [ Links ]
17. R.V. Griffith, J. Palfalvi, and U. Madhvanath (editors), Compendium of Neutron Spectra and Detector Responses for Radiation Protection Purposes. International Atomic Energy Agency, Technical Reports Series No 318. Vienna (1990). [ Links ]
18. R.V. Griffith, J. Palfalvi, and B.R.L. Siebert (editors), Compendium of Neutron Spectra and Detector Responses for Radiation Protection Purposes. Supplement to Technical Reports Series No. 318. International Atomic Energy Agency, Technical Reports Series No 403. Vienna (2001). [ Links ]
19. J.F. Briesmeister (editor), MCNPTM -A general Monte Carlo N-Particle Transport Code. Los Alamos National Laboratory Report LA-13709-M (2000). [ Links ]
20. ICRP, Conversion Coefficients for use in Radiological Protection against External Radiation, Publication 74, Annals of the ICRP 26 (3/4), International Commission on Radiological Protection, Pergamon Press, New York (1996). [ Links ]
21. H.R. Vega-Carrillo et al., Rev. Mex. Fís. 51 (2005) 494. [ Links ]
22. A.N. Garg and R.J. Batra, Journal of Radioanalytical and Nuclear Chemistry 98 (1986) 167. [ Links ] ]]>