Industrial X-ray Computed Tomography System Research Articles

Development of low-cost industrial x-ray computed tomography system based on digital fluoroscopy

Computed tomography (CT) offers an effective method of non-destructive testing for quality control in the manufacturing of complex parts. Using CT allows examination any internal anomaly of a sample like a defect, internal porosity, void detection, and cracks. However commercial X-ray CT equipment on markets is expensive. So it is required to develop low-cost X-ray CT equipment that provides good image quality and fast scanning. This paper describes the development of digital fluoroscopy-based X-ray CT system. It consists of an X-ray source, a rotary table system, a digital fluoroscopy detector, and a computer. This research uses a fluorescent screen to make the X-ray image visible which then digitized by a CMOS camera. The real-time radiographic image can be visualized and interpreted using a computer. These advantages make acquisition time for scanning images is reduced to only a few seconds. This equipment is relatively cheaper than the same system used in industry. It has been tested with an object of an aluminum step wedge cylinder by scanning 361 images, which were then reconstructed using the Octopus Reconstruction 8.9 software with a filtered back-projection method. The resulting image quality is quite good as it is easily interpreted by the user’s eyesight. The implication of this research is the possibility of producing a low-cost X-ray CT equipment made within the country.

Effects of off-focal radiation on dimensional measurements in industrial cone-beam micro-focus X-ray computed tomography systems

A study of the secondary source phenomenon due to the presence of off-focal radiation in industrial micro-focus cone-beam X-ray computed tomography (XCT) systems and its influence on dimensional measurements is presented. Although off-focal radiation production within X-ray tubes has been studied for medical X-ray imaging systems, its properties and its effects on dimensional measurements in industrial XCT systems have not been discussed prior to this research. The study comprises: evaluation of the geometrical properties of off-focal radiation through a theoretical and experimental study of two-dimensional projection images of the scanned objects, verification of these properties using computer simulations and evaluation of the impact of the secondary source on dimensional measurements using experimental and simulation approaches. In addition, ways to minimise the effects of off-focal radiation are discussed, and reference samples for characterising the properties of off-focal radiation are proposed.

443産業用高エネルギーX線CTとその応用

A high energy industrial X-ray computed tomography system using silicon semiconductor detectors (Si-SSD) and electron linear accelerator (LINAC) was developed to obtain high resolution 3D images of high density and large scale object. To increase photon sensitivity, detector elements were placed parallel to the X-ray beams. The obtained sensitivity of 20% for X-ray of 3MeV was 3×104 times higher than that of X-ray films. It was clarified that the photon sensitivity of X-ray detectors restricts the performance of high energy X-ray CT, and it is shown that a CT image of 200mm thick iron object can be obtained with 0.2mm space resolution.