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Title: Enhancing the quality of radiographic images acquired with point-like gamma-ray sources through correction of the beam divergence and attenuation

Radiographic images acquired with point-like gamma-ray sources exhibit a desirable low penumbra effects specially when positioned far away from the set object-detector. Such an arrangement frequently is not affordable due to the limited flux provided by a distant source. A closer source, however, has two main drawbacks, namely the degradation of the spatial resolution - as actual sources are only approximately punctual - and the non-homogeneity of the beam hitting the detector, which creates a false attenuation map of the object being inspected. This non-homogeneity is caused by the beam divergence itself and by the different thicknesses traversed the beam even if the object were an homogeneous flat plate. In this work, radiographic images of objects with different geometries, such as flat plates and pipes have undergone a correction of beam divergence and attenuation addressing the experimental verification of the capability and soundness of an algorithm formerly developed to generate and process synthetic images. The impact of other parameters, including source-detector gap, attenuation coefficient, ratio defective-to-main hull thickness and counting statistics have been assessed for specifically tailored test-objects aiming at the evaluation of the ability of the proposed method to deal with different boundary conditions. All experiments have been carriedmore » out with an X-ray sensitive Imaging Plate and reactor-produced {sup 198}Au and {sup 165}Dy sources. The results have been compared with other technique showing a better capability to correct the attenuation map of inspected objects unveiling their inner structure otherwise concealed by the poor contrast caused by the beam divergence and attenuation, in particular for those regions far apart from the vertical of the source.« less
Authors:
;  [1] ;  [2]
  1. Instituto de Engenharia Nuclear - CNEN, Caixa Postal 68550, CEP 21945-970, Rio de Janeiro (Brazil)
  2. Laboratório de Instrumentação Nuclear - UFRJ, Caixa Postal 68509, CEP 21945-970, Rio de Janeiro (Brazil)
Publication Date:
OSTI Identifier:
22390468
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1625; Journal Issue: 1; Conference: 36. Brazilian Workshop on Nuclear Physics, Sao Sebastiao, SP (Brazil), 1-5 Sep 2013; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; 07 ISOTOPES AND RADIATION SOURCES; ALGORITHMS; APPROXIMATIONS; ATTENUATION; BOUNDARY CONDITIONS; COMPARATIVE EVALUATIONS; CORRECTIONS; DYSPROSIUM 165; GAMMA RADIOGRAPHY; GAMMA SOURCES; GOLD 198; IMAGES; PLATES; SOUND WAVES; SPATIAL RESOLUTION; X RADIATION