Vol.2 No.3 2009

Research paper−221−Synthesiology - English edition Vol.2 No.3 pp.221-228 (Dec. 2009) development of a high-energy X-ray generator operable by batteries using a carbon nanostructure as an electron source. This X-ray generator produces X-rays of 100 keV or over with only one AA battery. In some conditions, 100 or more shots of high-resolution X-ray transmission images can be photographed. This performance is practical for a portable X-ray source. When used, the X-ray transmission evaluation can be conducted by carrying the X-ray source onto the site without an AC source or heavy batteries, and it is hoped to be a new X-ray source for nondestructive evaluations.In this paper, the development of the battery-operated high-energy X-ray generator is described, and consideration will be made of how the researches that we have been doing produced this result.2 A battery-operated portable high-energy X-ray sourceThe X-ray can be generated by accelerating the electron beam emitted from the cathode and injecting the beam onto a metal target. A conventional X-ray tube uses the thermionic emission phenomenon of the filament or heater to obtain thermionic electron emission from the cathode. Because of its structure, one must wait until the cathode temperature becomes constant, electricity must be constantly supplied to the heater, and power is consumed even when the X-ray is not being generated. The usability of the device as a portable X-ray source is compromised due to such issues.In the X-ray source using carbon nanostructure that was developed by the author et al.[1], X-rays at output equivalent or higher than the conventional X-ray source can be generated without the heater or the filament, and the issues of warm up 1 IntroductionIn Japan, there are many concrete structures and plant facilities that were built during the period of rapid economic growth, and aging of these structures has become an issue. To continue using the structures safely, it is necessary to deploy nondestructive evaluation in which the evaluation devices are carried onto the site to determine the deterioration condition without destroying the structure. There are various nondestructive evaluation methods using ultrasound, electromagnetic radiation, X-rays, or other radioactive rays. X-ray transmission allows imaging the inside of an object, just as in the roentgen exams of the human body. It is used in various fields since the test results can be seen and understood easily.However, when using X-ray transmission such as for wastage evaluation of pipes in a plant, high-energy X-ray is necessary for steel pipes, and since the device for X-ray source necessary for such tests is bulky and heavy, testing in small spaces is difficult. Also, an X-ray device with large output has further disadvantages. It requires a long time for the heater or filament to warm up and cannot be used instantly when it is necessary, and its energy consumption is large. In many cases evaluation using X-ray transmission may be dismissed due to poor usability. If such issues are solved, inspections can be done more frequently, thus reducing the possibility for failures and accidents.The author et al. set as an objective the development of a portable X-ray generation device that allows generation of high-energy high-output X-rays of 100 keV or over, and this device should be operable by power sources readily available such as dry cell batteries. As a result, we succeeded in the - Innovation in X-ray nondestructive evaluation -Ryoichi SuzukiResearch Institute of Instrumentation Frontier, AIST Tsukuba Central 2, 1-1-1 Umezono, Tsukuba 305-8568, Japan E-mail : Original manuscript received May 15, 2009, Revisions received July 14, 2009, Accepted July 16, 2009We have developed a practical portable high-energy X-ray source, which can generate high energy X-rays with energies greater than 100 keV enabling the taking of high-definition X-ray transmission images using an R6 (AA) battery as a power source. This result is a consequence of the integration of the compact and energy-saving electron accelerator technologies of AIST and the carbon nanostructure technologies of private companies. In this paper, we discuss these elemental technologies and how to integrate them.Development of battery-operated portable high-energy X-ray sourcesKeywords : X-ray, non-destructive evaluation, battery operated, electron accelerator, energy saving[Translation from Synthesiology, Vol.2, No.3, p.237-243 (2009)]


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