TY - CONF A1 - Bellon, Carsten A1 - Deresch, Andreas A1 - Gollwitzer, Christian A1 - Jaenisch, Gerd-Rüdiger T1 - Radiographic simulator aRTist: version 2 N2 - Computer simulation of radiography can be used for different purposes in NDT, such as qualification of NDT systems, optimization of radiographic parameters, feasibility analysis, model-based data interpretation, and training of NDT/NDE personnel. BAM has been working on modeling in the field of radiographic testing for many years. With the gathered theoretical background and the familiarity with practical requirements of industrial application the simulation software aRTist has been developed. This analytical simulator includes a description of the radiation source, the interaction of radiation with test pieces and flaws, and the detection process with special focus on film and digital industrial radiology. It features high processing speed with nearinteractive frame rates and a high level of realism. Here we focus on the recent developments of the simulator, notably the release of aRTist version 2. Extended functionality regarding automated virtual computed tomography now allows for arbitrary scan paths. Another program extension supports reliability investigations and provides a user interface for planning automatic simulations with varying parameters and defects. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 16.04.2012 KW - X-ray imaging KW - Radiographic testing KW - Simulation KW - Computed tomography PY - 2012 SN - 978-0-620-52872-6 SP - 1 EP - 7 (Paper 333) AN - OPUS4-27398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Warrikhoff, A. T1 - Simulating X-ray spectra: from tube parameters to detector output N2 - A model is discussed which describes the generation of X-rays in conventional tubes using tabulated bremsstrahlung energy spectra depending on three variables: the target atomic number, the incident electron kinetic energy, and the fraction of energy radiated. Additionally a parameter-free description of the characteristic radiation is included. The constructed model includes technical tube parameters like kilovoltage, target material, and angles of electron incidence and photon emission to also account for self-absorption in the target, as well as radiographic parameters like filtering. In order to verify model results, detector response is also considered. The validity of the proposed model is shown by measurements. Future work includes the extension of the model to transmission targets. This research was supported by the German Federal Ministry of Economics and Technology under contract MNPQ transfer II D 5-30/06. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 2012-04-16 KW - X-ray KW - Spectrum KW - Simulation PY - 2012 SN - 978-0-620-52872-6 SP - 1 EP - 8 (Paper 336) AN - OPUS4-27399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gollwitzer, Christian A1 - Bellon, Carsten A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger A1 - Baron, H.-U. A1 - Ewert, Uwe T1 - Reliability investigations of radiographic testing using aRTist as a simulation tool N2 - Within the framework of the European project PICASSO, the radiographic simulator aRTist (analytical Radiographic Testing inspection simulation tool) developed by BAM has been extended for reliability assessment of film and digital radiography. A simulation supported probability of detection (POD) methodology has been developed and the validity of the approach has been studied using an application from the aeronautics industry. An experimental POD has been determined with the help of a specialized software tool, developed to aid with the collection of large series of POD data. The resulting POD is compared to simulations of the same setting using aRTist and the newly available module for simulation supported POD. A quantitative agreement within a few percent is achieved between the experimental and the simulation supported POD. T2 - 18th WCNDT - World conference on nondestructive testing CY - Durban, South Africa DA - 2012-04-16 KW - X-ray imaging KW - Probability of detection KW - Simulation PY - 2012 SN - 978-0-620-52872-6 SP - 1 EP - 10 (Paper 338) AN - OPUS4-27400 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Schumm, A. A1 - Guerin, P. ED - Chimenti, D.E. ED - Bond, L.J. ED - Thompson, D.O. T1 - A proposed benchmark for simulation in radiographic testing N2 - The purpose of this benchmark study is to compare simulation results predicted by various models of radiographic testing, in particular those that are capable of separately predicting primary and scatter radiation for specimens of arbitrary geometry. T2 - 40th Annual review of progress in quantitative nondestructive evaluation CY - Baltimore, Maryland, USA DA - 21.07.2013 KW - Benchmark KW - Simulation KW - Radiographic testing PY - 2014 SN - 978-0-7354-1212-5 SN - 978-0-7354-1211-8 DO - https://doi.org/10.1063/1.4865082 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1581 SP - 2101 EP - 2106 PB - AIP Publishing AN - OPUS4-30756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - Zuverlässigkeit radiografischer Prüfungen und Simulationen T2 - DGZfP-Jahrestagung 2013 CY - Dresden, Germany DA - 2013-05-06 PY - 2013 AN - OPUS4-29751 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ewert, Uwe A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger ED - Chimenti, D.E. ED - Bond, L.J. ED - Thompson, D.O. T1 - A benchmark concept for simulation in radiographic testing N2 - The new standard ISO 17636–2:2013 'NDT of welds: Radiographic testing - Part 2: X- and gamma ray techniques with digital detectors' describes a complex procedure for film replacement by phosphor imaging plates and digital detector arrays. RT modeling software should consider these detector types, X-ray film, and the standard requirements for image quality. Practitioners expect the same visibility of image quality indicators (IQI) in the simulated radiographs as in the experimental exposures. The proposed benchmark test is based on the comparison of experimental radiographs taken at BAM with modeled ones of participants. The experimental setup and the determination of the equivalent penetrameter sensitivity (EPS) as described in the procedure of ASTM E 746 are used for quantitative evaluation of the achievable contrast sensitivity for step hole IQIs as considered in Annex B of ISO 17636-2. System classification data for Computed Radiography (CR) and film systems will be provided by BAM according to ISO 11699–1 for selected film systems and according to ASTM E 2446 for selected CR systems. The classification of films and digital detectors is based on the measurement of the dose response function, the basic spatial resolution (SRb) of the image, and the measured image noise, which depends on the detector efficiency, the quantum statistics, and the detector fixed pattern noise. T2 - 40th Annual review of progress in quantitative nondestructive evaluation CY - Baltimore, Maryland, USA DA - 21.07.2013 KW - Digital radiography KW - Computed radiography KW - Benchmark KW - EPS KW - Modeling KW - Simulation KW - Contrast to noise ratio KW - Observer model PY - 2014 SN - 978-0-7354-1212-5 SN - 978-0-7354-1211-8 DO - https://doi.org/10.1063/1.4865044 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 33A SP - 1816 EP - 1823 PB - AIP Publishing AN - OPUS4-30904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaenisch, Gerd-Rüdiger A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Schumm, A. A1 - Lucet-Sanchez, F. A1 - Guerin, P. ED - Chimenti, D.E. ED - Bond, L.J. T1 - Radiography benchmark 2014 N2 - The purpose of the 2014 WFNDEC RT benchmark study was to compare predictions of various models of radiographic techniques, in particular those that predict the contribution of scattered radiation. All calculations were carried out for homogenous materials and a mono-energetic X-ray point source in the energy range between 100 keV and 10 MeV. The calculations were to include the best physics approach available considering electron binding effects. Secondary effects like X-ray fluorescence and bremsstrahlung production were to be taken into account if possible. The problem to be considered had two parts. Part I examined the spectrum and the spatial distribution of radiation behind a single iron plate. Part II considered two equally sized plates, made of iron and aluminum respectively, only evaluating the spatial distribution. Here we present the results of above benchmark study, comparing them to MCNP as the assumed reference model. The possible origins of the observed deviations are discussed. T2 - 41st Annual review of progress in quantitative nondestructive evaluation CY - Boise, Idaho, USA DA - 20.07.2014 KW - Radiography KW - Spectrum KW - Modeling KW - Validation PY - 2015 SN - 978-0-7354-1292-7 DO - https://doi.org/10.1063/1.4914809 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1650 SP - 1834 EP - 1846 PB - AIP Publishing AN - OPUS4-33083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger A1 - Ewert, Uwe ED - Chimenti, D.E. ED - Bond, L.J. T1 - Fast model of electron transport for radiographic spectrum simulation N2 - Correctly modeling the continuous photon spectrum of X-ray tubes requires detailed knowledge of the probability distribution of electron properties at the time of X-ray photon creation, in particular electron energy, depth within the target, and direction of movement. Semi-analytical X-ray spectrum models frequently assume a very simplified or even uniform distribution of electron direction. In the case of thick targets and small deviations from normal incidence this is a useful approximation. For thin targets or large deviations from normal incidence the correct distribution of electron directions becomes more important. As calculation speed is an important aspect of semi-analytical models compared to Monte Carlo simulations, fast evaluation of the distribution of electron properties is highly desirable. The approach presented here numerically evaluates the evolution of a discrete probability distribution of electron properties due to single electron scatter interactions within a plane target. This allows capturing the important aspects of the electron distribution while achieving runtimes of a few seconds up to a minute on a standard office PC. T2 - 41st Annual review of progress in quantitative nondestructive evaluation CY - Boise, Idaho, USA DA - 20.07.2014 KW - Radiography KW - Spectrum KW - Modeling KW - Valildation PY - 2015 SN - 978-0-7354-1292-7 DO - https://doi.org/10.1063/1.4914656 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1650 SP - 579 EP - 585 PB - AIP Publishing AN - OPUS4-33082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - Durchstrahlungssimulation mit aRTist - Kombination von analytischen und Monte-Carlo-Methoden T2 - DACH-Jahrestagung 2015 CY - Salzburg, Austria DA - 2015-05-11 PY - 2015 AN - OPUS4-33586 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten A1 - Deresch, Andreas A1 - Jaenisch, Gerd-Rüdiger T1 - Radiography simulation with aRTist - Combining analytical and Monte Carlo methods N2 - Modelling becomes more and more important in modern NDE. It is increasingly used to optimize techniques for complex applications and to support the preparation of written procedures. Hence, computer simulation nowadays has to be able to handle all significant properties of an NDE system with sufficient accuracy. In case of radiographic applications this includes models of the radiation source, of the interaction of radiation with materials, of the detection process, and the geometrical description of the part or the construction. Depending on the given inspection problem and the influencing factors that should be addressed by the simulation an appropriate physical model has to be chosen to describe the underlying interaction mechanisms. The simulator aRTist combines analytical and Monte Carlo methods to efficiently model the radiation transport. Simulation is a powerful tool to separate different influencing factors. Here we focus on Monte-Carlo simulation of scatter contributions within aRTist. T2 - DIR 2015 - International symposium on digital industrial radiology and computed tomography CY - Ghent, Belgium DA - 22.06.2015 KW - CT KW - Multi-angle radiography KW - Modelling KW - Laminography KW - Radiographic testing (RT) PY - 2015 SP - 1 EP - 7 AN - OPUS4-33738 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - Radiography simulation with aRTist - combining analytical and Monte-Carlo methods T2 - Digital Industrial Radiology and Computed Tomography (DIR 2015) CY - Ghent, Belgium DA - 2015-06-22 PY - 2015 AN - OPUS4-33595 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Deresch, Andreas A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger T1 - A general spectrum model for X-ray generators N2 - A fast quantitative model for the energy spectra of radiation emitted by X-ray tubes is described, handling thin as well as thick plane targets of arbitrary materials. The developed model is based on fundamental interaction cross sections, describing electron and photon transport via numerical integration of discretized distributions. While the focus lies on bremsstrahlung production, modeling of characteristic radiation is fully integrated. The model does not include any free parameters. The validity of the model is shown through comparison with measurements and Monte Carlo simulations for several combinations of target material and acceleration potential between 30 kV and 450 kV. KW - Modeling KW - X-ray KW - Spectrum KW - Bremsstrahlung KW - Electron transport PY - 2016 DO - https://doi.org/10.1016/j.ndteint.2015.12.007 SN - 0963-8695 VL - 79 SP - 92 EP - 97 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-35263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumm, A. A1 - Duvauchelle, P. A1 - Kaftandjian, V. A1 - Jaenisch, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Tabary, J. A1 - Mathy, F. A1 - Legoupil, S. ED - Büyüköztürk, O. T1 - Modelling of radiographic inspections N2 - Computer modelling of non-destructive testing methods has come a long way from the beginnings in the mid 90s to today. Radiographic modelling for components with higher wall thicknesses, as they are typical for nuclear applications, must include precise predictions of scattered radiation and its impact in terms of contrast reduction. Dedicated or general purpose Monte Carlo methods with the ability to calculate higher order scattering events are the state of the art for these applications. Aerospace applications, on the other hand, have stronger requirements on the modelling code's capabilities to import complex CAD geometries, and can benefit from faster analytical scatter models, limited to first or second order scattering events. Similar distinctions can be made for the various approaches proposed to accurately model geometrical and film unsharpness, film granularity, film responses, film/foil cartridges and photon noise. This article presents a state-of-the-art review of radiographic modelling from the perspective of two important application domains with very different requirements, nuclear and aerospace. T2 - NDTMS-2011 CY - Istanbul, Turkey DA - 15.05.2011 KW - Computer modelling KW - Monte-Carlo KW - Radiography KW - Film KW - Selenium PY - 2013 SN - 978-94-007-0722-1 SN - 978-94-007-0723-8 DO - https://doi.org/10.1007/978-94-007-0723-8_99 VL - 6 SP - 697 EP - 702 PB - Springer Netherlands AN - OPUS4-36655 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Christina A1 - Tillack, Gerd-Rüdiger A1 - Bellon, Carsten A1 - Scharmach, Martina T1 - Wie kann man den Einfluß der industriellen Anwendungsfaktoren innerhalb der ZfP-Zuverlaessigkeitsformel messen? N2 - Dieses Poster beschäftigt sich mit der Zuverlässigkeitsformel und der Metrik für die Messung der Zuverlässigkeit T2 - DGZfP Jahrestagung 2000 CY - Innsbruck, Austria DA - 29.05.2000 KW - Anwendungszuverlässigkeit KW - Anwendungsparameter KW - ZfP-System PY - 2000 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-35849 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - Combining analytical and Monte Carlo modelling for industrial radiology N2 - Modelling becomes more and more important in modern NDE. It is increasingly used to optimize techniques for complex applications, to support the preparation of written procedures, and for education purposes. To describe the complete chain of RT, the model includes simulating all necessary properties of X- or Gamma-ray sources, the interaction of photons with material with special attention to scattered radiation, the detection process, and the complete geometrical RT setup handling arbitrary parts or constructions. Depending on the given inspection problem and the influencing factors that should be addressed by the simulation, an appropriate physical model has to be chosen to describe the underlying interaction mechanisms. The simulator aRTist combines analytical and Monte Carlo methods to efficiently model the radiation transport such that transmission as well as scatter techniques can be modelled. In this contribution we focus on Monte Carlo simulation of scatter contribution within aRTist. Examples for RT/tomographic applications and back-scatter techniques are presented to demonstrate the usability of the presented simulation tool for a broad range of radiological applications. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Monte Carlo method KW - Radiography KW - Simulation PY - 2016 AN - OPUS4-36617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten T1 - A fast general spectrum model for quantitative radiography simulation N2 - A model is presented that employs a unified approach for simulating the photon energy spectra for transmission and direct beam targets composed of arbitrary homogeneous materials. In order to achieve this, a detailed model of electron transport within the target is employed. The validity of the developed model is shown through comparisons with Monte Carlo simulations as well as measurements for a number of different configurations. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Modelling KW - Radiography KW - Simulation KW - X-ray spectrum PY - 2016 AN - OPUS4-36628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bellon, Carsten A1 - Jaenisch, Gerd-Rüdiger T1 - Supercomputing the cascade processes of radiation transport N2 - Modeling of the photon-electron cascade process in multicomponent objects of complex geometrical structure by use of hybrid supercomputers is considered. An approach to computing the cascade processes is developed. The approach has three key properties allowing the effective use of heterogeneous structure of computers for solving the tasks of radiation transport in complex multi-scale geometries. Firstly, two different discreet geometrical description of an object being under radiation is used: triangulated model for photon transport and voxel model for elec-tron transport. Secondly, small parameter of the problem is explicitly taking into ac-count for modeling surface effects (for instance, electron emission). Thirdly, the ef-fective calculation decomposition between CPU and GPU is developed for signifi-cant increasing the speed of calculations of processes in question. Modeling of ex-periment on researching the bremsstrahlung generated by electron beam in Ta target is carried out. Comparison of computing and experimental results shows satisfactory consent. T2 - 19th World Conference on Non-Destructive Testing CY - Munich, Germany DA - 13.06.2016 KW - Modelling KW - Monte Carlo method KW - Photon-electron transport PY - 2016 AN - OPUS4-36608 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hilpert, U. A1 - Bartscher, M. A1 - Neugebauer, M. A1 - Goebbels, Jürgen A1 - Weidemann, Gerd A1 - Bellon, Carsten T1 - Simulation-aided computed tomography (CT) for dimensional measurements N2 - Carrying out dimensional measurements by CT means assessing coordinates in space. CT must therefore be treated as a coordinate measuring technique similar to optical or tactile Coordinate Measuring Machines (CMMs). The well-established standards and guidelines for the acceptance- and verificationtesting of CMMs require the use of calibrated reference standards to achieve measurement machine characteristics. Hence, transferring these concepts from coordinate metrology to CT, a dedicated CT-specific reference standard was designed, manufactured and calibrated using a tactile CMM. For comparison purposes, a CAD model was created by reverse engineering using the calibration data. The calibrated model was fed into a virtual CT and the measurement process was simulated. The reference standard was measured by micro-CT. By comparing the characteristics of the measurement output of CT and the output gained from simulation, the influences of measurement artefacts can be judged, for the first time, in analogy to existing Guidelines of coordinate metrology. T2 - DIR 2007 - International Symposium on Digital industrial Radiology and Computed Tomography CY - Lyon, France DA - 25.06.2007 KW - Computed tomography KW - X-ray KW - Simulation KW - Coordinate metrology PY - 2007 UR - http://www.ndt.net/article/dir2007/papers/12.pdf SP - Paper 6, 1 EP - 15 AN - OPUS4-37045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ewert, Uwe A1 - Martin Tschaikner, Martin A1 - Hohendorf, Stefan A1 - Bellon, Carsten A1 - Haith, M. I. A1 - Huthwaite, P. A1 - Lowe, M. J. S. T1 - Corrosion monitoring with tangential radiography and limited view computed tomography N2 - Accurate and reliable detection of subsea Pipeline corrosion is required in order to verify the integrity of the pipeline. A laboratory trial was conducted with a representative pipe sample. The accurate measurement of the wall thickness and corrosion was performed with high energy X-rays and a digital detector array. A 7.5 MV betatron was used to penetrate a stepped pipe and a welded test pipe of 3 m length and 327 mm outer diameter, with different artificial corrosion areas in the 24 mm thick steel wall. The radiographs were taken with a 40 x 40 cm² digital detector array, which was not large enough to cover the complete pipe diameter after magnification. A C-arm based geometry was tested to evaluate the potential for automated inspection in field. The primary goal was the accurate measurement of wall thickness conforming to the standard. The same geometry was used to explore the ability of a C-arm based scanner in asymmetric mode for computed tomography (CT) measurement, taking projections covering only two thirds of the pipe diameter. The technique was optimized with the modelling Software aRTist. A full volume of the pipe was reconstructed and the CT data set was used for reverse engineering, providing a CAD file for further aRTist simulations to explore the technique for subsea inspections. T2 - 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Minneapolis, Minnesota, USA DA - 26.07.2015 KW - Corrosion monitoring KW - Tangential radiography KW - Computed tomography PY - 2016 SN - 978-0-7354-1353-5 DO - https://doi.org/10.1063/1.4940574 SN - 0094-243X VL - 1706 SP - 110003-1 EP - 110003-8 PB - AIP Publishing AN - OPUS4-37555 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Haith, M. I. A1 - Ewert, Uwe A1 - Hohendorf, Stefan A1 - Bellon, Carsten A1 - Deresch, Andreas A1 - Huthwaite, P. A1 - Lowe, M. J. S. A1 - Zscherpel, Uwe T1 - Radiographic modelling for NDE of subsea pipelines N2 - This work presents an investigation of the accuracy of a radiographic simulation model applied to subsea pipeline inspections. Experimental measurements of a sample in a water tank are used to develop a set of calibrated simulation parameters for the modelling software aRTist. Image quality parameters such as signal-tonoise ratio, contrast and basic spatial resolution are compared with the aim of matching simulated values to experimental results. With this method signal-to-noise ratio was successfully matched while differences were still found in contrast-to-noise ratio comparisons. This means that measurements depending on absolute intensity are not accurate enough, however wall thickness measurements in tangential images, which are not based on absolute intensity, were found to produce similar results in simulated and experimental cases. The differences in contrast and intensity are thought to be due to detector backscatter and additional scatter from out-of-setup objects within the exposure bay, due to a lack of source collimation. These would affect the experimental results but were not included in the simulated setup. This was investigated by including different proportions of peripheral water and other objects in the modelled setup and examining the effect on Image quality parameters. Results show that this additional scatter has a significant impact on the radiograph, particularly on image contrast, and is therefore the likely cause of differences between experimental and simulated images. This implies that it will be very difficult to completely match simulated to experimental results, as including all possible scattering objects in the model would be very complex. An improvement could be made by using real subsea data to estimate this additional scattering, which could then be used to calibrate the model. However there would still be significant uncertainty in the ability of the model to accurately produce realistic intensity and contrast. KW - Digital radiography KW - Modelling validation KW - Subsea pipeline inspection KW - Tangential radiography PY - 2017 DO - https://doi.org/10.1016/j.ndteint.2016.11.006 SN - 0963-8695 SN - 1879-1174 VL - 86 SP - 113 EP - 122 AN - OPUS4-39053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -