• Title, Summary, Keyword: X-ray

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Development and Characteristics of the Soft x-ray transmission W-target tube (W-target 투과 양극형 Soft x-ray tube의 개발 및 특성분석)

  • Kim, Sung-Soo;Kim, Do-Yun
    • Journal of the Korean Vacuum Society
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    • v.16 no.4
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    • pp.305-310
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    • 2007
  • The x-ray transmission W-target tube was developed and its characteristics were evaluated. The continuous x-ray was emitted at the tube voltage less than 12kV, and the characteristic x-ray was emitted more than 12kV. From the measurement of the energy distribution and dose of x-ray, it was confirmed that our results are a good agreement with the blown ones. Moreover, in comparison with commercial x-ray tube, it was also found that the characteristics of our x-ray tube is better than the commercial one. Therefore we confirmed that the x-ray tube developed in this study is so good that it can be commercialized.

Development of X-ray PIV System Using a Medical X-ray Tube (임상용 X-선관을 이용한 X-ray PIV시스템의 개발)

  • Yim, Dae-Hyun;Kim, Guk-Bae;Kim, Do-Il;Lee, Hyong-Koo;Lee, Sang-Joon
    • 유체기계공업학회:학술대회논문집
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    • pp.403-406
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    • 2006
  • A new medical X-ray PIV technique was developed using a conventional medical X-ray tube. To acquire images of micro-scale particles, the X-ray PIV system consists of an x-ray CCD camera with high spatial resolution, and a X-ray tube with small a focal spot. A new X-ray exposure control device was developed using a rotating disc shutter to make double pulses which are essential for PIV application. Synchronization methodology was also developed to apply the PIV technique to a conventional medical X-ray tube. In order to check the performance and usefulness of the developed X-ray PIV technique, it was applied to a glycerin flow in an opaque silicon tube. Tungsten particles which have high X-ray absorption coefficient were used as tracer particles. Through this preliminary test, the spatial resolution was found to be higher than ultrafast MRI techniques, and the temporal resolution was higher than conventional X-ray PIV techniques. By improving its performance further and developing more suitable tracers, this medical X-ray PIV technique will have strong potential in the fields of medical imaging or nondestructive inspection as well as diagnosis of practical thermo-fluid flows.

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Detection Probabilities of the X-ray Point Sources in X-ray Extended Sources

  • Kim, Min-Sun;Kim, Eun-Hyeuk
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.33.2-33.2
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    • 2010
  • Galaxy clusters are known to be very bright in X-ray and contain a large number of X-ray point sources within the X-ray emission. However, due to the fluctuations of the X-ray emission, it is very difficult to detect faint X-ray sources and to extract accurately the photometric properties of the X-ray point sources in galaxy clusters. In addition, the most X-ray telescopes show spatially varying point spread function (PSF) and suffer from severe vignetting. The Chandra Archival Survey of Galaxy Clusters project is a wide-area ($\sim40deg^2$) survey of serendipitous Chandra X-ray sources in galaxy cluster fields, containing ~58,000 X-ray point sources in ~800 Chandra ACIS observations of ~600 galaxy clusters. This project aim to investigate the density environmental effects on the physical properties of the X-ray point sources, comparing physical properties of the X-ray point sources in galaxy clusters to those in typical fields. To utilize the sensitivity and detection probability of the X-ray point sources in galaxy clusters, we perform extensive Monte-Carlo simulations. In this poster, we compare the detection probability of the X-ray point sources in galaxy clusters to that of typical fields, and discuss quantitatively the difference between them.

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A Comparative Study on Output of Four Type Diagnostic X-ray Equipments (정류방식에 따른 진단용 X-선 장치의 출력비교)

  • Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.20 no.2
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    • pp.34-43
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    • 1997
  • There are 4 types of equipment in diagnostic radiography. These are single phase, three phase, inverter type and condenser type X-ray generators. It is very confusing to make an adequate exposure factor and to know the usage of different type of X-ray generators. In this experiment, I explored a comparative study of outputs in 4 different type of X-ray units. I expect that this experiment could be helpful for manufacturer to make both the X-ray equipment better, In terms of Ideal exposure factors, thereby reducing the patient dose. Experimental results are as follow : 1) X-ray output The ratio of X-ray output of single, three phase and inverter type of X-ray generator was 1 : 1.6 : 2 without absorber and 1 : 2 : 2.6 with 20 mm aluminium absorber. 2) Beam quality The X-ray beam quality of single phase generator was proved to be softer than three phase and inverter type of generators by 0.4 mmAL and 0.55 mmAl HVL respectively. 3) Reproducibility Linearity of X-ray output Retroducibility of X-ray output met the regulation below CV 0.05 and linearity also met the regulation below 0.1 in 4 types of diagnostic X-ray generators. 4) The comparison of incident dose Three phase X-ray generator was 20% higher than two other X-ray generators in radiation dose to make same film density.

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An Intraoral Miniature X-ray Tube Based on Carbon Nanotubes for Dental Radiography

  • Kim, Hyun Jin;Kim, Hyun Nam;Raza, Hamid Saeed;Park, Han Beom;Cho, Sung Oh
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.799-804
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    • 2016
  • A miniature X-ray tube based on a carbon-nanotube electron emitter has been employed for the application to a dental radiography. The miniature X-ray tube has an outer diameter of 7 mm and a length of 47 mm. The miniature X-ray tube is operated in a negative high-voltage mode in which the X-ray target is electrically grounded. In addition, X-rays are generated only to the teeth directions using a collimator while X-rays generated to other directions are shielded. Hence, the X-ray tube can be safely inserted into a human mouth. Using the intra-oral X-ray tube, a dental radiography is demonstrated where the positions of an X-ray source and a sensor are reversed compared with a conventional dental radiography system. X-ray images of five neighboring teeth are obtained and, furthermore, both left and right molar images are achieved by a single X-ray shot of the miniature X-ray tube.

Introduction to Properties of Galactic-X-ray Sources

  • Choi, Chul-Sung;Min, Kyoung-W.;Kim, Tu-Hwan
    • Journal of Astronomy and Space Sciences
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    • v.5 no.2
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    • pp.143-158
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    • 1988
  • Since the successful observation by Uhuru, the first astronomical satellite, X-ray astronomy has become one of the rapidly developing fields in astronomy. The scientific results provide us the unique opportunity to understand the high energy nature of X-ray sources. We now know that our galaxy contains many different types of X-ray sources such as the compact X-ray sources, galactic bulge sources in addition to the Sun, the brightest X-ray sources in the sky. In this study we review the general properties of galactic X-ray sources, the characteristics of periodic compact X-ray sources, and bursters as well as the models.

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Study about sacral base X-ray of Barge (Barge의 천골 기저부 X-ray에 대한 연구)

  • Min, Young-Kwang
    • The Journal of Korea CHUNA Manual Medicine for Spine and Nerves
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    • v.6 no.1
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    • pp.19-26
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    • 2011
  • Objectives : The purpose of this study is to research the necessity of sacral base X-ray that Barge insisted. Methods : I have done a comparative analysis in side of short leg and side of sacral inferior with sacral base X-ray and pelvis A-P Xray pictures of 42 patients with lower back pain from December 1, 2010 to March 31, 2011. Results : Even though most of the subjects in study were male, 36 people had plateau of sacral base and 29 people had symmetry in sacral base X-ray. There was no statistical significance in the side of short leg and side of sacral base inferior in Sacral base X-ray, but there was a statistical significance in pelvis A-P x-ray. 22 people had same side of short leg and side of sacral base inferior in sacral base X-ray and pelvis A-P X-ray and 14 people didn't. 29 people had same side of sacral base inferior in sacral base X-ray and pelvis A-P X-ray and 13 people didn't. Conclusions : According to the result of the study, sacral base X-ray is necessary for correct sacral base inferior analysis.

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SPECTROSCOPIC STUDIES IN X-RAY ASTRONOMY (X-선 천문 분야의 분광관측 연구)

  • CHOI CHUL-SUNG
    • Publications of The Korean Astronomical Society
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    • v.15 no.spc1
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    • pp.73-83
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    • 2000
  • X-ray astronomy deals with measurements of the electromagnetic radiation in the energy range of $E\~0.1-100 keV (\lambda\~0.12-120{\AA})$. The wavelength of X-ray is comparable to the size of atoms, so that the photons in the X-ray range are usually produced and absorbed by the atomic processes. Since the launch of the first X-ray astronomy satellite 'Uhuru' in 1970, technological advances in a launch capability and a detection capability make X-ray astronomy one of the most rapidly evolving fields of astronomical research. Particularly, a spectral resolving power $E/{\Delta}E$ has been increased by an order of 2 - 3 (in the energy range of 0.1 - 10 keV) during the past 30years. In this paper, I briefly review a developing process of the resolving power and spectroscopic techniques. Then I describe important emission/absorption lines in X-ray astronomy, as well as diagnostics of gas property with line parameters.

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Wireless Triggering Pulse Generation for Digital X-ray Imaging System (디지털 x-ray 영상시스템을 위한 무선 트리거 발생기)

  • Ko, Dae-Sik;Lee, Jae-Cheol;Lee, Joo-Shin
    • Journal of Advanced Navigation Technology
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    • v.11 no.2
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    • pp.163-169
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    • 2007
  • In this paper, we propose a method of trigger pulse generation to capture the image on time by making a synchronization between the x-ray generator and digital x-ray image acquisition system. we designed a wireless trigger pulse generation circuit to make a synchronization between x-ray generator and digital image acquisition system and analysis its performance. When it starts to detect a certain level of x-ray radiation or above from the air, this method starts to generate a ACQ_START signal to indicate the timing for image acquisition starting from digital image acquisition system. Hence, when it starts to detect under certain level of x-ray signal from the air, this method starts to generate a ACC_END signal to indicate the timing for image acquisition stop from digital image acquisition system. Image acquisition is activated only this time between ACQ_START and ACQ_END signal. By doing this wireless detecting of x-ray signal from remote, we can get more accurate timing for capturing the x-ray image and any type of x-ray generator can be connected to digital image acquisition system, regards of wired protocol. This makes easy installation. We could get 3.5 line pair / mm resolution at 20 mAs of x-ray level with resolution chart. This is same or better image comparing to conventional wired result.

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Development of Diode Based High Energy X-ray Spatial Dose Distribution Measuring Device

  • Lee, Jeonghee;Kim, Ikhyun;Park, Jong-Won;Lim, Yong-Kon;Moon, Myungkook;Lee, Sangheon;Lim, Chang Hwy
    • Journal of Radiation Protection and Research
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    • v.43 no.3
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    • pp.97-106
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    • 2018
  • Background: A cargo container scanner using a high-energy X-ray generates a fan beam X-ray to acquire a transmitted image. Because the generated X-rays by LINAC may affect the image quality and radiation protection of the system, it is necessary to acquire accurate information about the generated X-ray beam distribution. In this paper, a diode-based multi-channel spatial dose measuring device for measuring the X-ray dose distribution developed for measuring the high energy X-ray beam distribution of the container scanner is described. Materials and Methods: The developed high-energy X-ray spatial dose distribution measuring device can measure the spatial distribution of X-rays using 128 diode-based X-ray sensors. And precise measurement of the beam distribution is possible through automatic positioning in the vertical and horizontal directions. The response characteristics of the measurement system were evaluated by comparing the signal gain difference of each pixel, response linearity according to X-ray incident dose change, evaluation of resolution, and measurement of two-dimensional spatial beam distribution. Results and Discussion: As a result, it was found that the difference between the maximum value and the minimum value of the response signal according to the incident position showed a difference of about 10%, and the response signal was linearly increased. And it has been confirmed that high-resolution and two-dimensional measurements are possible. Conclusion: The developed X-ray spatial dose measuring device was evaluated as suitable for dose measurement of high energy X-ray through confirmation of linearity of response signal, spatial uniformity, high resolution measuring ability and ability to measure spatial dose. We will perform precise measurement of the X-ray beamline in the container scanning system using the X-ray spatial dose distribution measuring device developed through this research.