Simulación por Monte Carlo de la respuesta en eficiencia de un detector HPGe tipo pozo a la energía de 46.54 keV

Yasser Morera Gómez, Héctor A. Cartas Águila, Carlos M. Alonso Hernández, José L. Bernal Castillo

Resumen

En el trabajo se utilizaron los métodos de simulación por Monte Carlo en un detector HPGe tipo pozo, usando directamente los parámetros del fabricante para simular la respuesta en eficiencia a la energía de 46.54 keV. Los valores de efi ciencia se calcularon en función de la altura de la muestra en la geometría de medición y los resultados se correspondieron con los valores experimentales. Las mayores diferencias fueron menores que el 2.5 % con un promedio de 0.9 %, lo que es totalmente satisfactorio para la medición de muestras ambientales. Se presentó una breve discusión sobre la respuesta del detector para diferentes parámetros geométrico.

Palabras clave

detectores de Ge ultrapuro; método de Monte Carlo; calibración; precisión; eficiencia

Texto completo:

PDF Epub HTML

Referencias

RENFRO AA, COCHRAN JK, COLLE BA. Atmospheric fluxes of 7Be and 210Pb on monthly time-scales and during rainfall events at Stony Brook, New York (USA). J Environ Radioact. 2013; 116: 114-123. doi:10.1016/j.jenvrad.2012.09.007.

ALONSO HERNÁNDEZ CM, MORERA GÓMEZ Y, CARTAS ÁGUILA H, GUILLÉN ARRUEBARRENA A. Atmospheric deposition patterns of 210Pb and 7Be in Cienfuegos, Cuba. J Environ Radioact. 2014; 138: 149-155. doi:10.1016/j.jenvrad.2014.08.023.

BASKARAN M. Po-210 and Pb-210 as atmospheric tracers and global atmospheric Pb-210 fallout: a Review. J Environ Radioact. 2011; 102(5): 500-513. doi:10.1016/j.jenvrad.2010.10.007.

ABRIL JM, BRUNSKILL GJ. Evidence that excess Pb-210 flux varies with sediment accumulation rate and implications for dating recent sediments. J Paleolimnol. 2014; 52(3): 121-137. doi:10.1007/s10933-014-9782-6.

SAARI HK, SCHMIDT S, CASTAING P, et. al. The particulate 7Be/210Pbxs and 234Th/210Pbxs activity ratios as tracers for tidal-to-seasonal particle dynamics in the Gironde estuary (France): implications for the budget of particle-associated contaminants. Sci Total Environ. 2010; 408(20): 4784-4794.

VARGAS MJ, TIMÓN AF, DÍAZ NC, SÁNCHEZ DP. Monte Carlo simulation of the self-absorption corrections for natural samples in gamma-ray spectrometry. Appl. Radiat. Isot. 2002; 57(6): 893-898.

SAÏDOU, BOCHUD F, LAEDERMANN JP, et. al. Calibration of an HPGe detector and self-attenuation correction for 210Pb: Verification by alpha spectrometry of 210Po in environmental samples. Nucl Instruments Methods Phys Res Sect. 2007; 578(3): 515-522.

LABORIE JM, LE PETIT G, ABT D, GIRARD M. Monte carlo calculation of the efficiency calibration curve and coincidence-summing corrections in low-level gamma-ray spectrometry using well-type HPGe detectors. Appl. Radiat.Isot. 2000; 53(1-2): 57-62.

BOSON J, AGREN G, JOHANSSON L. A detailed investigation of HPGe detector response for improved Monte Carlo efficiency calculations. Nucl Instruments Methods Phys Res Sect. 2008; 587(2-3): 304-314.

MORERA GÓMEZ Y, CARTAS AGUILA HA, ALONSO HERNÁNDEZ CM, et. al. Application of the Monte Carlo efficiency transfer method to an HPGe detector with the purpose of environmental samples measurement. Appl. Radiat. Isot. 2015; 97: 59-62. doi:10.1016/j.apradiso.2014.12.013.

DÍAZ RIZO O, LÓPEZ PINO N, D’ALESSANDRO K, et. al. Characterization of the InSTECs low-background gamma spectrometer for environmental radioactivity studies. Nucleus. 2009; (46): 21-26.

ELANIQUE A, MARZOCCHI O, LEONE D, HEGENBART L, BREUSTEDT B, OUFNI L. Dead layer thickness characterization of an HPGe detector by measurements and Monte Carlo simulations. Appl. Radiat. Isot. 2012; 70(3): 538-542.

BUDJAZ D, HEISEL M, MANESCHG W, SIMGEN H. Optimisation of the MC-model of a p-type Ge-spectrometer for the purpose of efficiency determination. Appl. Radiat. Isot. 2009; 67(5): 706-710.

PADILLA CABAL F, LOPEZ PINO N, LUIS BERNAL CASTILLO J, et al. Monte Carlo based geometrical model for efficiency calculation of an n-type HPGe detector. Appl. Radiat. Isot. 2010; 68(12): 2403-2408.

HERNÁNDEZ F, EL-DAOUSHY F. Accounting for incomplete charge collection in Monte Carlo simulations of the efficiency of well-type Ge-detectors. Nucl Instruments Methods Phys Res Sect. 2003; 498(1-3): 340-351.

COURTINE F, PILLEYRE T, SANZELLE S & MIALLIER D. Ge well detector calibration by means of a trial and error procedure using the dead layers as a unique parameter in a Monte Carlo simulation. Nucl Instruments Methods Phys Res Sect Accel Spectrometers Detect Assoc Equip. 2008; 596(2): 229-234.

STEGER HF, BOWMAN WS. DL-1a: A certificated uranium-thorium reference ore. CANMET Reportm80-10E. Ottawa: CANMET; 1980.

LINSINGER T. Comparison of a measurement result with the certified value. Application Note 1 [online]. European Reference Materials, 2010. .

RÓDENAS J, PASCUAL A, ZARZA I, et. al. Analysis of the influence of germanium dead layer on detector calibration simulation for environmental radioactive samples using the Monte Carlo method. Nucl Instruments Methods Phys Res Sect. 2003; 496(2-3): 390-399.

BOCHUD F, BAILAT CJ, BUCHILLIER T, et. al. Simple Monte-Carlo method to calibrate well-type HPGe detectors. Nucl Instruments Methods Phys Res Sect. 2006; 569(3): 790-795.

PÉREZ MORENO JP, BOLÍVAR JP, GARCÍA TENORIO R, et al. A simple method for efficiency calibration of HPGe detectors in gamma-spectrometric measurements. Radiat. Phys. Chem. 2001; 61(3-6): 437-438.

SAN MIGUEL EG, PÉREZ MORENO JP, BOLÍVAR JP, et. al. 210Pb determination by gamma spectrometry in voluminal samples (cylindrical geometry). Nucl Instruments Methods Phys Res Sect. 2002; 493(1-2): 111-120.