• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.795-798
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• 2016

Transmission X-ray tubes based on carbon nanotube have attracted significant attention recently. In most of these tubes, tungsten is used as the target material. In this article, the well-known simulator Geant4 was used to obtain some of the tungsten target parameters. The optimal thickness for maximum production of usable X-rays when the target is exposed to electron beams of different energies was obtained. The linear variation of optimal thickness of the target for different electron energies was also obtained. The data obtained in this study can be used to design X-ray tubes. A beryllium window was considered for the X-ray tube. The X-ray energy spectra at the moment of production and after passing through the target and window for different electron energies in the 30-110 keV range were also obtained. The results obtained show that with a specific thickness, the target material itself can act as filter, which enables generation of X-rays with a limited energy.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.355-356
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• 2016

기존 X-ray용 인버터의 경우, 일반적인 Full-bridge 인버터를 사용하여 낮은 효율이 발생하기 때문에 1.6kW이상의 고전압 출력을 요구하는 X-ray를 사용할 수 없는 문제점이 있다. 본 논문은 X-ray 구동용 인버터의 높은 출력이 가능한 고전압 출력용 ZVS Phase-Shift Full Bridge 인버터를 제안한다. 기존의 X-ray 구동용 인버터를 사용할 경우에는 낮은 효율 및 높은 출력 전압을 발생 시킬 수 없기 때문에 X-ray 발생이 어려우며, 높은 출력을 발생시키기 위해서는 회로의 전체적인 부피가 커지고 제작단가가 증가하는 단점이 있다. 반면 제안된 회로는 X-ray 구동용 ZVS Phase-Shift Full Bridge 인버터로써, 영전압 스위칭을 통해 높은 효율로 인버터 구동이 가능하고, 높은 출력 전압을 발생 시킬 수 있기 때문에 회로의 소형화 및 고출력 X-ray 발생이 가능한 장점을 갖는다. 본 논문에서는 제안된 회로의 이론적인 특성을 분석하고 모의실험을 통해 확인하였으며, 1.6kW급 X-ray 구동 인버터 회로에 적용하여 실험을 통해 우수성을 검증하였다.

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.264-265
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• 2005

In this paper the conceptual design and development of a compact vertical type soft x-ray microscope is described. This x-ray microscope operates in the water window wavelength region(2.3 ${\sim}$ 4.4nm), where natural contrast between carbon(protein) and oxygen(water) allows imaging of unstained biological material their natural, hydrated environment. Until now, operational x-ray microscopes are based on synchrotron radiation sources, which limit their accessibility. Many biologists would benefit from having the x-ray microscope as a tool among other tools in their own laboratory, For this purpose we introduced the compact vertical type soft X-ray microscope with 50 nm resolution for biomedical application. The compact vertical type soft x-ray microscope is based on a laser plasma x-ray source, doubled ellipsoidal condenser reflective optics, diffractive zone plate optics and MCP coupled with CCD to record an x-ray image.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.762-763
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• 2010

The X-ray device used for medical treatment is classified into fixed type that is used by installing at the location with the stable power supply and mobile type that can be taken by moving the X-ray device to the location where a patient is. Mobile X-ray device which is typically used in the mobile type of X-ray can be used very usefully beyond the space restriction. However, due to its difficulty to generate high-voltage, it is mainly applied to take hand and foot shootings which only need low output power. In this study, by designing and producing the large volume of mobile X-ray device which doesn't have the limitations on diagnostic areas of the body, the operating characteristics of device according to the loading change was identified.

• Journal of radiological science and technology
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• v.18 no.2
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• pp.61-73
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• 1995

For the managements of the diagnostic X-ray equipments, the authors examined the output of single phase rectification assembly, Three phase rectification assembly and serial radiographic appartus, and got the following conclusions. 1. When the tube voltages in X-ray control panels ware compared to the measured values on the kVp pulse meter, only little differences were detected in all the X-ray equipments. And most of the equipments were all well managed within the internationally permitted limits, excepting the 12.02 % error at 120 kVp in three phase rectifying assembly. 2. As for the X-ray qualities affecting the X-ray images, the serial radiographic apparatus showed excellence, while the single phase rectification assembly were somewhat inferior to the others only maining the internationally recommended limits. 3. The tube voltage ranges where the X-ray output showed excellence were $100{\sim}200\;mA$ in serial radiographic apparatus, $200{\sim}350\;mA$ in three phase rectification assembly and $350{\sim}400\;mA$ in single phase rectification assembly respectively. 4. In the repeatability test of the X-ray equipments, CVs were in the range of $0.0029{\sim}0.049$, which is within the HEW or KS standards. Consequently all the equipments are thought to be well-manage. 5. This study on characteristics and output of the X-ray equipments was accomplished within a limited short time. Long-time researches on the function managements for the X-ray equipments should be followed along with the periodical checking the output for reduction of X-ray exposures to the patients or radio-technologists, and for maintanance and prediction of trouble of the equipments.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.465-471
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• 2012

In this study, three dimensional X-ray dose distribution from dental X-ray generator system was measured by ALOKA PDM-117 dosimeter. The X-ray dose distribution will be change with XCP-DS FIT in oral shot, because the distance between X-ray generator and the dosimeter. The X-ray dose change affects on patient exposure and radiograph image quality. Therefore, it is important to obtain relation between the X-ray dose and the distance. The X-ray dose at the central position was decreased with increasing the distance. Furthermore, the dose at the edge of the X-ray flux was increased with increasing the distance. The increased dose affects on the patient radiation exposure. The present results will provide for good dental radiograph image and reducing radiation over-exposure on patient.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.1
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• pp.46-53
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• 2010

A Compton X-ray backscatter technique has been developed to quantitatively assess impact damage in quasi-isotropic laminated composites made by a drop-weight tester. X-ray backscatter imaging system with a slit-type camera is constructed to obtain a cross-sectional profile of impact-damaged laminated composites from the electron-density variation of the cross section. A nonlinear scattering model based on Boltsman equation is introduced to compute Compton X-ray backscattering field for the defect assessment. An adaptive filter is also used to reduce noises from many sources including quantum noise and irregular distributions of fibers and matrix in composites. Delaminations masked or distorted by the first delamination are detected and characterized effectively by the Compton X-ray backscatter technique, both in width and location, by application of error minimization algorithm.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1297-1303
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• 2021

Most thickness measurement techniques using X-ray radiation are unsuitable in field processes involving fast-moving organic films. Herein, we propose a Compton scattering X-ray radiation method, which probes the light elements in organic materials, and a new simple, non-destructive, and non-contact calibration-free real-time film thickness measurement technique by setting up a bench-top X-ray thickness measurement system simulating a field process dealing with thin flexible organic films. The use of X-ray fluorescence and Compton scattering X-ray radiation reflectance signals from films in close contact with a roller produced accurate thickness measurements. In a high-thickness range, the contribution of X-ray fluorescence is negligible, whereas that of Compton scattering is negligible in a low-thickness range. X-ray fluorescence and Compton scattering show good correlations with the organic film thickness (R² = 0.997 and 0.999 for X-ray fluorescence and Compton scattering, respectively, in the thickness range 0-0.5 mm). Although the sensitivity of X-ray fluorescence is approximately 4.6 times higher than that of Compton scattering, Compton scattering signals are useful for thick films (e.g., thicker than ca. 1-5 mm under our present experiment conditions). Thus, successful calibration-free thickness monitoring is possible for fast-moving films, as demonstrated in our experiments.

• Journal of Radiation Protection and Research
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• v.44 no.2
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• pp.72-78
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• 2019

Background: In the calibration and testing laboratory of Korea Atomic Energy Research Institute, the old X-ray generator used for the production of reference X-ray fields was replaced with a new one. For this newly installed X-ray irradiation system, beam alignment as well as the verification of beam qualities was conducted. Materials and Methods: The existing X-ray generator, Phillips MG325, was replaced with YXLON Y.TU 320-D03 in order to generate reference X-ray fields. Theoretical calculations and Monte Carlo simulations were used to determine initial filter thickness. Beam alignment was performed in three steps to deliver a homogeneous radiation dosage to the target at different distances. Finally, the half-value layers were measured for different X-ray fields to verify beam qualities by using an ion chamber. Results and Discussion: Beam alignment was performed in three steps, and collimators and other components were arranged to maintain the uniformity of the mean air kerma rate within ${\pm}2.5%$ at the effective beam diameter of 28 cm. The beam quality was verified by using half-value layer measurement methods specified by American National Standard Institute (ANSI) N13.11-2009 and International Organization for Standardization (ISO)-4037. For each of the nine beams than can be generated by the new X-ray irradiation system, air kerma rates for X-ray fields of different beam qualifies were measured. The results showed that each air kerma rate and homogeneity coefficient of the first and second half-value layers were within ${\pm}5%$ of the recommended values in the standard documents. Conclusion: The results showed that the new X-ray irradiation system provides beam qualities that are as high as moderate beam qualities offered by National Institute of Standards and Technology in ANSI N13.11-2009 and those for narrow-spectrum series of ISO-4037.

• Journal of Advanced Technology Convergence
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• v.2 no.1
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• pp.17-21
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• 2023

In this study, using an X-ray device (Drgem TS-CSP) and foot phantom (SFT-1556), the angle of the X-ray tube was changed to 30°, 35°, 40°, 45°, and 50°, and the image was evaluated by quantitative and qualitative evaluation. In the blind test, it was the highest at 4.34 points at 40°, and in the part calculation using the Image J program, the angle was the largest at 1750 at 50°. In addition, in the area evaluation excluding overlapping areas, the X-ray tube showed the largest value at 40° Therefore, it was found that the X-ray tube angle was suitable when the X-ray tube angle was 40° as a projection method for observing the calcaneus.