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The comparison of four neutron sources for Prompt Gamma Neutron Activation Analysis (PGNAA) in vivo detections of boron.

Fantidis JG, Nicolaou GE, Potolias C, Vordos N, Bandekas DV - J Radioanal Nucl Chem (2011)

Bottom Line: In this work the optimisation procedure is demonstrated for boron.Monte Carlo calculations were carried out to compare the performance of the proposed PGNAA system using four different neutron sources ((241)Am/Be, (252)Cf, (241)Am/B, and DT neutron generator).Among the different systems the (252)Cf neutron based PGNAA system has the best performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Kavala Institute of Technology, Kavala, Greece.

ABSTRACT

A Prompt Gamma Ray Neutron Activation Analysis (PGNAA) system, incorporating an isotopic neutron source has been simulated using the MCNPX Monte Carlo code. In order to improve the signal to noise ratio different collimators and a filter were placed between the neutron source and the object. The effect of the positioning of the neutron beam and the detector relative to the object has been studied. In this work the optimisation procedure is demonstrated for boron. Monte Carlo calculations were carried out to compare the performance of the proposed PGNAA system using four different neutron sources ((241)Am/Be, (252)Cf, (241)Am/B, and DT neutron generator). Among the different systems the (252)Cf neutron based PGNAA system has the best performance.

No MeSH data available.


Top view of the simulated experimental set-up (not in scale)
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Fig3: Top view of the simulated experimental set-up (not in scale)

Mentions: In order to see the effect of source positioning on neutron flux distribution, the 252Cf neutron source was placed at different positions along the z+ and z− directions (Fig. 1). Three energy ranges are considered: thermal neutrons (0.01–0.3 eV), epithermal neutrons (0.3 eV–10 keV), and fast neutrons (above 10 keV). Neutron fluxes were calculated in region #1 (Fig. 3) using the F4 tally with NPS = 107 histories yielding an accuracy <1%. Region #1 is a cube with a side of 8 cm, which is symmetrically placed on the x axis. It is seen that the source at z = −2 cm is the optimum position (Fig. 4). At z = −2 cm the 252Cf neutron source produce the highest value for the thermal and epithermal neutron flux and the lowest value for the fast fluence rate. The comparison of the neutron spectrum in region #1 between the symmetrical case with no filter and in case with source at the best positions is illustrated in Fig. 5.Fig. 3


The comparison of four neutron sources for Prompt Gamma Neutron Activation Analysis (PGNAA) in vivo detections of boron.

Fantidis JG, Nicolaou GE, Potolias C, Vordos N, Bandekas DV - J Radioanal Nucl Chem (2011)

Top view of the simulated experimental set-up (not in scale)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4514448&req=5

Fig3: Top view of the simulated experimental set-up (not in scale)
Mentions: In order to see the effect of source positioning on neutron flux distribution, the 252Cf neutron source was placed at different positions along the z+ and z− directions (Fig. 1). Three energy ranges are considered: thermal neutrons (0.01–0.3 eV), epithermal neutrons (0.3 eV–10 keV), and fast neutrons (above 10 keV). Neutron fluxes were calculated in region #1 (Fig. 3) using the F4 tally with NPS = 107 histories yielding an accuracy <1%. Region #1 is a cube with a side of 8 cm, which is symmetrically placed on the x axis. It is seen that the source at z = −2 cm is the optimum position (Fig. 4). At z = −2 cm the 252Cf neutron source produce the highest value for the thermal and epithermal neutron flux and the lowest value for the fast fluence rate. The comparison of the neutron spectrum in region #1 between the symmetrical case with no filter and in case with source at the best positions is illustrated in Fig. 5.Fig. 3

Bottom Line: In this work the optimisation procedure is demonstrated for boron.Monte Carlo calculations were carried out to compare the performance of the proposed PGNAA system using four different neutron sources ((241)Am/Be, (252)Cf, (241)Am/B, and DT neutron generator).Among the different systems the (252)Cf neutron based PGNAA system has the best performance.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, Kavala Institute of Technology, Kavala, Greece.

ABSTRACT

A Prompt Gamma Ray Neutron Activation Analysis (PGNAA) system, incorporating an isotopic neutron source has been simulated using the MCNPX Monte Carlo code. In order to improve the signal to noise ratio different collimators and a filter were placed between the neutron source and the object. The effect of the positioning of the neutron beam and the detector relative to the object has been studied. In this work the optimisation procedure is demonstrated for boron. Monte Carlo calculations were carried out to compare the performance of the proposed PGNAA system using four different neutron sources ((241)Am/Be, (252)Cf, (241)Am/B, and DT neutron generator). Among the different systems the (252)Cf neutron based PGNAA system has the best performance.

No MeSH data available.