پیاده‎ سازی مقطع‌نگاری رایانه‌ای نوترونی (nCT) با روش بازسازی تصاویر FBP در راکتور تحقیقاتی تهران

نوع مقاله : مقاله پژوهشی

نویسندگان

1 پژوهشگاه علوم و فنون هسته ای

2 dr

3 d

چکیده

تصویربرداری مقطع‌نگاری رایانه‌ای نوترونی، یکی از روش‌های تصویربرداری سه بعدی نوین و با دقت بالا برای بازرسی و آزمون غیرمخرب مواد و قطعات است. تصویر حجمی ایجادشده توسط این روش، برای بررسی ساختار داخلی، شناسایی عیوب و سنجش کیفیت نمونه‌های مورد آزمون بسیار کارآمد است. در این تحقیق، پیاده‌‎سازی مقطع‌نگاری رایانه‌ای نوترونی با روش بازسازی تصاویر FBP در راکتور تحقیقاتی تهران برای اولین بار در کشور مورد مطالعه قرار گرفته است. سامانه شامل سیستم داده‌برداری تجربی، سیستم اتوماسیون یکپارچه تصویربرداری دیجیتال، پردازش و بازسازی تصویر با روش FBP و نمایش سه بعدی از حجم نمونه طراحی و راه‌اندازی گردیده است. نمونه مورد آزمون در میدان حاصل از باریکه نوترونی، به صورت نیم‌صفحه‌ای چرخانده و تعداد 360 پروجکشن دو بعدی تصویربرداری شده است. تصاویر پروجکشن با استفاده از نرم‌‎‏افزار MuhRec پیش‌پردازش و تصاویر مقطع‌نگاری با استفاده از الگوریتم FBP بازسازی شده‌اند. براساس نتایج، کیفیت تصاویر حاصل از بازسازی مناسب ارزیابی می‌شود. عیوب داخلی نمونه با توجه به بیشینه قدرت تفکیک مکانی سامانه در حدود µm 200، قابل تشخیص می‌باشند.

کلیدواژه‌ها


عنوان مقاله [English]

Implementation of the neutron computed tomography by means of Filtered-back Projection algorithm in Tehran Research Reactor

نویسندگان [English]

  • Nafise Araghian 1
  • Amir Movafeghi 2
  • Behrouz Rokrok 1
  • Mojtaba Farazmahdi 3
  • Mohammad Hosein Mansouri 3
  • Zeinab Naghshnezhad 2
1 Nuclear Science and Technology Institute (NSTRI)
2 dr
3 d
چکیده [English]

Neutron Computed Tomography (nCT) is proposed as one of the modern and high accuracy 3-dimensional imaging modalities of nondestructive testing of the materials and components. Volumetric rendering and representation capability of tomographic imaging has many advantages for interrogating the internal structures, defect detection and quality testing of objects. Implementation of Filtered Back-Projection (FBP) reconstruction method for nCT facility at Tehran Research Reactor has been investigated in this study. The facility consists of experimental data acquisition system, integrated automation digital imaging system, image processing, FBP reconstruction, and 3D visualization softwares. Test subject was turned within the neutron radiation field at half screen and 360 two-dimensional projections were acquired through data acquisition. Preprocessing was performed on projections and tomographic images of subject were reconstructed using MuhrRec software and FBP algorithm. The results were indicated that reconstructed images have appropriate quality. Internal defects were recognizable having dimensions above the maximum spatial resolution of the facility (~200 µm).

کلیدواژه‌ها [English]

  • Neutron Computed Tomography (nCT)
  • Tehran Research Reactor
  • Non-Destructive Testing (NDT)
  • CT Image Reconstruction with FBP method
[1] S. Carmignato and W.D., Richard Leach, Industrial X-Ray Computed Tomography. Springer, 2018.
[2] The Noble Prize, https://www.nobelprize.org/prizes/medicine/1979, retrived: January 2022.
[3] International American Society for Testing and Material, Standard Guide for Computed Tomography (CT) Imaging. Standard ASTM E1441, 2011.
[4] International American Society for Testing and Material, Standard Practice for Computed Tomography (CT) Examination. Standard ASTM E1570, 2011.
[5] International American Society for Testing and Material, Standard Guide for Computed Tomography (CT) System Selection. Standard ASTM E1672, 2001
[6] International American Society for Testing and Material, Standard Practice for Computed Tomography (CT) Examination of Casting. Standard ASTM E1814.
[7] International American Society for Testing and Material, Standard Guide for Compton Tomography (CT), Standard ASTM E1931.
[8] International American Society for Testing and Material, Standard Test Method for Measurement of Computed Tomography (CT) System Performance. Standard ASTM E1695, 2013.
[9] International American Society for Testing and Material, Standard Test Method for Measurement of Calibrating and Measuring CT Density. Standard ASTM E1635, 2013.
[10] International American Society for Testing and Material, Standards Practice for Digital Imaging and Communication in Nondestructive Evaluation (DICONDE) for X-ray Computed Tomography (CT) Test Methods. Standard ASTM E2767, 2011.
[11] M. Strobl, et al., Advances in neutron radiography and tomography. Journal of Physics D: Applied. Physics, Vol. 42, No. 24, p. 243001, 2009.
[12] International Society for Neutron Radiography (ISNR), https://www.isnr.de/index.php/facilities/facilities-worlwide.
[13] E. Lehmann, Neutron Imaging Facilities in a Global Context. Journal of Imaging, Vol. 3, 2017.
[14] K.K. Moghadam, Z. Tabatabaeian and N. Mirhabibi. Neutron Radiography Facility for AEOI Nuclear Research Center, in: Neutron Radiography, edited by J. P. Barton et al. Springer, Netherlands, 1987.
[15] K.K. Moghadam and F. Ziaie, Modification of the neutron beam spectrum for neutron radiography at Tehran Research Reactor (TRR). Nuclear Instruments and Methods in Physics Research A, Vol. 337, 1996.
[16] M.H. Choopan Dastjerdi, Examination of domestic nuclear fuel by design and construction of a new neutron radiography system at Tehran Research Reactor, Nuclear Science and Technology Research Institute, Iran, Ph.D. Thesis (2016) (In Persian).
[17] International American Society for Testing and Material, Standard Method for Determining Image Quality in Direct Thermal Neutron Radiographic Examination. Standard ASTM E545, Vol. 4, 2005.
[18] B. Rokrok, et al., Design and construction of the neutron facility for Tehran Research Reactor with real-time digital imaging capability, Nondestructive Testing Technology, Vol. 2, No. 7, 2021. (In Persian)
[19] A. P. Kaestner, MuhRec—A new tomography reconstructor. Nuclear Instrument and Methods Physics Research Section A, Vol. 651, No. 1, 2011.
[20] J. T. Bushberg, et al. The essential physics of medical imaging, Lippincott Williams and Wilkins, Philadelphia, PA, 2020.
[21] E. Seeram, Computed Tomography: Physical Principles, Clinical Applications, and Quality Control, Elsevier Health Sciences, 2015.
[22] Hsieh, J., Computed Tomography: Principles, Design, Artifacts, and Recent Advances, SPIE and John Wiley & Sons, Washington and New Jersey, Inc. 2009.
[23] M. Morgano, et al., Unlocking high spatial resolution in neutron imaging through an add-on fibre optics taper, Optics Express,Vol. 26, No. 2, p. 1809-16, 2018.