• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.3026-3034
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• 2021

Multi-target X-ray tube is a new type X-ray source, and can be applied in many fields such as sensitive X-ray fluorescence analysis and medical imaging. In this work, we report an electric field modulation multi-target X-ray tube, which contains four targets (Cr, Ni, Au, Mo) coated on a Beryllium (Be) window. A four-valve electric field deflector was developed to deflect the electron beam to bombard the corresponding targets. Particle dynamics analysis software was employed to simulate the particle tracking of electron beam. The results show that the 30 keV electron beam could get a 6.7 mm displacement on the target plane by 10⁵ V/m electric field. The focus areas are about 2 mm × 5 mm and 4 mm × 2.5 mm after deflection in two directions. Thermal behavior calculated by ANSYS shows that the designed target assembly could withstand a 10 W continuous power. The optimum target thicknesses and emission spectra were obtained by Geant4 when the thickness of Be window was 300 mm and the electron beam incident angle was 0.141 rad. The results indicate that this multi-target X-ray tube could provide different X-ray sources effectively.

• Journal of the Korean Society of Radiology
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• v.13 no.7
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• pp.979-986
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• 2019

The purpose of this study devised a method for the examination of the images of the first and second rib fractures of the axillary using Rib Rando Phantom. The position of the phantom and the angle of the X-ray tube were changed to vertical, head 5° and foot 5°. The Radiological Technologists subjectively evaluated the acquired images and the evaluation data were analyzed by SPSS 3.0 ver. The signal to noise ratio(SNR) was calculated using the ImageJ Program. As a result, the cronbach alpha value was significantly higher at 0.789. The SNR was highest at 6.038 when the X-ray tube was tilted 5° toward the head in the front of the ribs and highest at 7.860 when the X-ray tube was tilted 5° toward the foot. Radiographic Techniques proposed axillary ribs this study are as follows. The anterior rib scan is examined by elevating the fractured area and changing the X-ray tube angle by 5° towards the head. The posterior ribs scan is examined by attaching the fractured area and changing to the X-ray tube angle by 5° towards the foot. It is considered that such an inspection method can obtain a sharp image.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.327-333
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• 2023

In Order to Diagnose Maxillary Bone and Maxillary Sinus in the X-Ray Paranasal Sinus Projection test, this Study used Skull Rando Phantom to Change the Posture and X-ray tube Angle to 5° of the Head or 5° of ROC Who worked for more than 10 years. The Significance of the Evaluated score was Verified through SPSS Ver. 3.0, and the Cronbach value was Significantly higher at 0.712. In addition, as a Result of Calculating SNR by Setting the ROI(Receiver Operation Characteristic) of the Maxillary bone and Maxillary sinus images, it was the Highest at 6,449 in the Examination by tilting 5° toward the Head or Leg of the X-ray tube. In the study, it is believed that among the X-Ray simple Paranasal Sinus projection tests, a sharp Image can be Obtained during the Examination by Tilting the X-ray tube 5° toward the Head or Leg.

• Journal of radiological science and technology
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• v.23 no.2
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• pp.27-32
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• 2000

It was produced radiation dosimeter used photo-diodes for which ionization by x-ray was applied and evaluated the value of utility in clinics as compared with ion-chamber. The result obtained were as follows : 1. Comparison of ion-chamber with photo-diode dosimeter's x-ray output by the change of x-ray tube voltage, and the ratio of ion-chamber to diode was $0.96{\sim}1.02$ which was not affected by x-ray beam quality. 2. The ratio of ion-chamber to diode was 0.96 by change of tube current and 0.97 by change of exposure time that is not affected by x-ray quantity. 3. The ratio of ion-chamber to diode was $0.97{\sim}1.04$ by thickness and $0.93{\sim}1.10$ by radiation field that is little affected by second ray quantity. 4. Reproducibility of photo-diode dosimeter was 0.011(CV) and it is a good result. 5. Photo-diode dosimeter was affected by the surface angle of detector over 30 degrees. Produced dosimeter was small, light, and meets good result compared with ionization chamber. It was expected come into wide use in clinic.

• Journal of the Korean Society of Radiology
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• v.13 no.3
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• pp.425-431
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• 2019

The Study In order to obtain images of overlap of the two iron cores in the spinal cord simple x-ray scan after surgery of patients with ulcer lateral sclerosis and a fractured backbone, the researcher conducted a subjective evaluation on five radiographers of the university hospital's imaging department for more than 10 years. The results of the experiment showed that the lateral shot of lateral scoliosis of the spinal cord was taken with the middle face of the IR plane, and then the X-ray tube angle was taken vertically with the vertical spinal column fan-tom position, resulting in two overlapping images and high scores in the subjective evaluation. In addition, lateral shots of the lumbar dislocation fractured lumbar vertebrae were taken with the forehead aligned with the center of the IR plane and then with the X-ray angle perpendicular to the fourth waistline and the angle of the spinal cord perpendicular to the fourth waistline, the image of the two iron cores could be obtained from the radiographer.

• Journal of radiological science and technology
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• v.43 no.3
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• pp.161-167
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• 2020

This study aimed to found out the effect of patellofemoral overlap distance by changing femur thickness and center X-ray angles in Merchant method images. Based on the femur thickness, it suggested tube angle minimizes overlap. It was conducted by Merchant method, a knee tangential view, and the image was obtained by changing the thigh thickness from 14 to 20 cm and the center ray angle from 60°, 57°, 55°. The images were measured by five researchers using a method of measuring the overlap, which was designed by them. The results showed at 60°, 57°, 55° angle, the patellofemoral overlap distance resulted in 0.47±0.66 to 20.89±0.65 cm, 2.26±0.28 to 15.73±0.62 cm, 1.39 ± 0.83 to 12.49 ± 0.37 cm. However, for 57° and 55°, no overlap in thickness under 14.5 and 14 to 15.5 didn't appear. it showed high correlation between femur thickness and overlap. The difference in the mean value of overlap in each group showed a statistically significant difference (p<0.01), all were classified as independent groups in the post-hoc test. In all images, the patellofemoral overlap distance increased as the thickness increased, and at the average thickness of Korean men and women, overlap decreased when reducing center ray. When conducting Merchant tests on Koreans, it was suggested it would be useful to use 57° angle because it minimize the effects of overlap and intrusions of tibia.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.577-584
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• 2014

In this study, the behavior of a shaped charge projectile's metal jet was analyzed using flash radiography. The projectile was installed horizontally to observe the behavior of jet for enough time. While the X-ray tube heads are fixed at one point, the behavior range of the jet is wide in this experimental set up, therefore the angle between the X-ray tube heads and the jet tip is changed continuously as jet moves forward. Jet particle's locations calculated from the X-ray films become different from their real positions under this situation because of the film to object distance(FTOD) and correction for error by FTOD is required. In this study, a method was devised to correct the error by FTOD and this was applied for the investigation of jet behavior of a 70 mm caliber's shaped charge.

• Journal of the Korean Society of Radiology
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• v.5 no.5
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• pp.223-229
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• 2011

When negative electron in x-ray tube is accelerated in to a high speed and then the currency of the electron is blocked by the target, x-ray happens by the conversion of the energy. The real area where the fast accelerated electron collides to a target area is called actual focal spot. When the string focused size is observed at the central ray side, where the direction x-ray comes out, the size seems to be reduced. This focus is called effective focal spot. According to radiation angle of x-rays tube, the degree of the negative pole side presents higher value than inclination, the amount of exposed radiation that patient receives differs by the angle of positive pole, which means effective focal spot is the variable. This paper presents the correlation between size of effective focal spot and amount of exposed radiation to the patient by it, and effective research for homogenized dose dispersion by the size of effective focal spot. In conclusion, following the focal size, effective range which was -8cm ~ 0 cm on average, was found and average dose rate was 0.019 R/min. Through this range, for patients with small radiation exposure, image with good density and resolution in aspect of diagnosing will be able to be obtained.

• Journal of the Korean Wood Science and Technology
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• v.34 no.1
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• pp.15-22
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• 2006

ln order to manage efficiently many ancient wooden buildings, which have been preserved as cultural properties in Korea, the internal state of wood members should be evaluated exactly and periodically by a NDE (non-destructive evaluation) method. A research project was planned to develop an X-ray CT (computed tomography) system as a NDE method for wood, which could be easily applied in field. This paper includes the first part of this project. First of all, to establish a measuring procedure of wood density using X-ray radiography, the correlation between X-ray intensity and the film brightness was evaluated. Also, initial X-ray intensity was quantified with various radiate conditions controlled by the tube voltage and tube current. And then, the effects of density, annual ring angle, and thickness on the mass attenuation coefficient of wood were examined. Finally, Beer's law was modified with the above results and adopted to calculate the density of wood. As a result of this study, the measuring procedure of wood density was established using a portable soft X-ray device and this procedure was verified with some small wood specimens. This results will he used valuably for the following researches to develop a portable X-ray CT system.

• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.919-926
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• 2021

In this study, we wanted to find out the optimal angle as a modified tangential projection of the patella. In the experiment, we used Kyoto Kagaku's PBU-50 phantom. In the supine position, the F-T angle was set to 95°, 105°, 115°, 125°, 135°, 145°, and Patella tangential projection images were obtained by varying the X-ray tube angle by 5° so that the angle between the X-ray centerline and tibia at each angle was 5~20°. Image J was used for image analysis and the congruence angle, lateral patellofemoral angle, patellofemoral index and contrast to noise ratio(CNR) were also measured. SPSS 22 was used for statistical analysis, and the mean values of congruence angle, patellofemoral angle, patellofemoral index, and CNR were compared with Merchant method through one-way batch analysis and corresponding sample t-test. As a result of the study, in the case of congruence angle, the angle of incidence of the knee-angle X-ray centerline was 105°-72.5° (20° tangential irradiation), 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-82.5° (20° tangential irradiation), lateral patellofemoral angle is 115°-72.5°, 77.5° (15, 20° tangential irradiation), 125°-72.5° (10° tangential irradiation), patellofemoral index is 115°-72.5° (15° tangential irradiation) and 125°-72.5° (10° tangential irradiation) were not significantly different from Merchant method (p> .05). In case of CNR, it is not different from Merchant method at 105°-67.5°, 72.5° (15, 20° tangential irradiation), 115°-67.5°, 72.5°, 77.5° (10, 15, 20° tangential irradiation). (P> .05). Based on the results of this study, high diagnostic value images can be obtained by setting the knee angle and the angle of incidence of the X-ray tube to 115°-72.5° (15° tangential irradiation) during the modified tangential examination of the knee bone. It was confirmed.