Performance Evaluation of a Gamma-Ray Imaging System for Nondestructive Testing of Welded Pipes


As a continuation of our radiographic testing (RT) R&D, we have developed a gamma-ray imaging system to be suitable for nondestructive testing of welded pipes. The system consists of an imaging detector having a CdTe/CMOS-based pixel array (AJAT, SCAN1000), a collimated 75Se gamma source having about 78.7 Ci activities, a gear track mounted around test pipes for image scan, and a computer-controlled microstep motor for precise control of the scan speed. All the components of the imaging system were assembled tightly by a chain belt. From the imaging system, we obtained useful gamma images of a stainless steel pipe (30 cm in internal diameter and 1 cm in thickness) having a weld line. Using standard techniques for evaluation of the radiography quality, we assessed the imaging characteristics of the detector in terms of the modulation transfer function (MTF), the noise power spectrum (NPS), and the detective quantum efficiency (DQE). © 2010 Elsevier B.V.


Nuclear Engineering and Radiation Science

Keywords and Phrases

Gamma-Ray Imaging System; Image Quality; Nondestructive Testing; Welded Pipes

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 2011 Elsevier, All rights reserved.

Publication Date

01 Jan 2011