Abstract: The use of portable and high-energy x-ray system can provide a very promising approach for the inspection of aged concrete structures. However, due to the effect of large scattering of low-energy x-ray in a thick concrete, the noise properties and contrast of the radiographic images need to be optimized to ensure reliable interpretation. Therefore, in order to improve the inspection ability, an image denoising method with the combination of wavelet and curvelet transform and image contrast e...
英字タイトル:
Image Enhancement for Concrete Bridge Inspection with Portable 950 keV/ 3.95 MeV X-ray Source

We are developing portable non-destructive testing (NDT) X-ray source with X-band linac and low power magnetron. Now, we start the experiment of electron acceleration and X-ray generation using by 950 keV X-band linac NDT system. The 950 keV X-band linac X-ray generator is under development for corrosion wastage of tubes and condition bas ed maintenance of impeller pumps. However, about 1 MeV X-ray source can be only used for thin tubes of about 20 mm thickness. Therefore, we start to design about 4 MeV X-...
英字タイトル:
Development of High Energy X-ray NDT System with 3.95 MeV X-band Linac

Abstract: Since more and more bridges built several decades ago in Japan have become aged and dangerous, the non-destructive evaluation of those bridges is really an urgent problem. CT system with portable 3.95MeV linacs for bridge inspection is considered to work on-site, considering the law of Japanese radiation protection allows using linacs up to 4MeV outside radiation controlled area. The system would confirm the internal steel si tuation of bridges and analyze structural strain and stress with 3D mod...
英字タイトル:
On-Site Bridge Inspection with Partial CT by 3.95Mev X-Band Linac Source

In situ CT application for NDE of degradation bridges is under development, with portable 950keV/3.95 MeV X-band linac as x-ray source. Collimator is adopted to reduce scattered X-ray noise. Material analysis and erosion estimation through dl-energy CT method is integrated in order to inspect the erosion situation of i nner steel rod. Reconstruction technique with incomplete projection data is studd considering limitation of projection angle range during onsite scanning. Furt hermore, based on 3D model bui...
英字タイトル:
Partial Inspection and Dual-energy CT Material Analysis with 950keV/3.95MeV X-Band Linac

Asakura's method is well known as the evaluation method of tsunami wave force. In this method, tsunami wave force is evaluated on the assumption that the inundation depth increases by 3 times in front of a structure. On the other hands, inundation depth is not constant around a cylindrical tank. Therefore, there is the possibility that the tsunami wave force of a cylindrical tank is overestimated by Asakura's method. In this paper, Sano's method is introduced as the evaluation method of tsunami wave force a...
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Evaluation Method of Tsunami Wave Force Acting on Cylindrical Tank

Our portable X-band (9.3GHz) 950KeV linac has been successfully upgraded. The problems of RF power oscillation , beam current oscillation and reduction and finally lack of X-ray intensity were solved by replacing the axia l coupling cavities with the side-coupled ones. Designed X-ray dose rate of 0.05 Sv/min@lm is going to be achi eved. Length of the accelerating tube is reduced to less than 25 cm. X-ray source part with the local radiation shielding is connected by the flexible waveguide with the box of t...
英字タイトル:
Study on Portable X-band 950keV linac X-ray Sourcefor On-site Nondestructive Inspection

Recently, the particularity of the working environment in the field of space and oceanic research lead to evelop the remote handling technology and the remote maintenance technology. Additionally, in the field f nuclear technology, such as hot laboratory, it is very important to develop the remote maintenance echnology. Espec ially, in the case of the hot laboratory to handle the irradiated fuel assembly containing he plutonium, the large scale cell equipped with shielding ability and sealing performance i...
英字タイトル:
Applying the remote maintenance technology to the Large scale hot laboratory