• Title/Summary/Keyword: 방사선량계

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The Response Correction Function of TL Dosimeter for Shallow Dose Assessment in Tl-204 Beta Fields (Tl-204 베타선장에서의 피부선량평가를 위한 열형광선량계의 베타보정함수)

  • Lee, Sang-Yoon;Kim, Jang-Lyul;Seo, Kyung-Won
    • Nuclear Engineering and Technology
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    • v.26 no.3
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    • pp.381-388
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    • 1994
  • Recently, the American National Standards Institute (ANSI) had made some changes in the radiation sources specified from those in the original performance test criteria ANSI N13. 11-1983. In case or beta category, in addition to the high-energy $^{90}$ Sr/$^{90}$ Y beta source, the $^{204}$ Tl source was added because many workplaces have significant levels of lower energy betas. In this study, the performance or the Teledyne PB-3 personnel dosimetry system in the fields of $^{204}$ Tl and $^{90}$ Sr/ $^{90}$ Y beta was investigated using the PTB beta secondary standard sources. The new beta correction function of PB-3 personnel dosimetry system for $^{204}$ Tl beta was also developed in this response experiment. The results show that the Teledyne PB-3 personnel dosimetry system is very effective for $^{90}$ Sr/ $^{90}$ Y beta dose assessment. In case of $^{204}$ Tl beta radiation, however, the results of simple performance test indicated that the use of beta correction factor(=2.088) which was recommanded by manufacturer may result in unexpectable overestimation of delivered dose by about 60%, while the use of developed beta correction function could measure the delivered doses in errors of 15%.

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Calibration Examination of Dose Area Product Meters using X-ray (X선을 이용한 면적선량계의 교정 연구)

  • Jung, Jae Eun;Won, Do-Yeon;Jung, Hong-Moon;Kweon, Dae Cheol
    • Journal of the Korean Society of Radiology
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    • v.11 no.1
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    • pp.37-42
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    • 2017
  • We measured the absorbed dose and the area dose using an ionization chamber type of area dose product (DAP) meter and measured the calibration factor in the X-ray examination. In the indirect dose measurement method, the detector was installed in the radiation part of the X-ray equipment, and the measured value was calculated as the dose at the exposure part. The instrument used to calculate the calibration factor was an X-ray equipment (DK-550R / F, DongKang Medical Co., Ltd., Seoul, Korea). The calibration method for the calibration factor was to connect the DAP meter (PD-8100, Toreck Co. Ltd., Japan) to the calibration dosimeter tube voltage of 70 kV, tube current of 500 mA, 0.158 sec. The reference dosimeter used a semiconductor (DOSIMAX plus A, Scanditronix, $Wellh{\ddot{o}}fer$, Germany). After installing the DAP meter on the front of the multi-collimator of the ionization chamber, the calibration factor of the dosimeter was obtained using the reference dosimeter for accurate dose measurement. Experimental exposure values and values from the calibration dosimeter were calculated by multiplying each calibration factor. The calibration factor was calculated as 1.045. In order to calculate the calibration coefficient according to the tube voltage in the ionization type DAP dosimeter, the absorbed dose and the area dose were calculated and the calibration factor was calculated. The corrective area dose was calculated by calculating the calibration factor of the DAP meter.

Development of ACBIO: A Biosphere Template Using AMBER for a Potential Radioactive Waste Repository (AMBER를 이용한 방사성폐기물처분장 생태계 평가 템플릿 ACBIO 개발)

  • Lee Youn-Myoung;Hwang Yongsoo;Kang Chul-Hyung;Hahn Pil-Soo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.3 no.3
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    • pp.213-229
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    • 2005
  • Nuclides in radioactive wastes are assumed to be transported in the geosphere by groundwater and probably discharged into the biosphere. Quantitative evaluation of doses to human beings due to nuclide transport in the geosphere and through the various pathways in the biosphere is the final step of safety assessment of the radioactive waste repository. To calculate the flux to dose conversion factors (DCFs) for nuclides appearing at GBIs with their decay chains, a template ACBIO which is an AMBER case file based on mathematical model for the mass transfer coefficients between the compartments has been developed considering material balance among the compartments in biosphere and then implementing to AMBER, a general and flexible software tool that allows to build dynamic compartment models. An illustrative calculation with ACBIO is shown.

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Absorbed and effective dose for periapical radiography using portable and wall type dental X-ray machines (이동형 구내방사선촬영기와 벽걸이 구내방사선촬영기로 촬영한 치근단 방사선촬영에서 환자의 흡수선량과 유효선량 평가)

  • Han, Won-Jeong
    • The Journal of Korean Academy of Prosthodontics
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    • v.50 no.3
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    • pp.184-190
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    • 2012
  • Purpose: The purpose of this study was to measure the absorbed dose and to calculate the effective dose for one periapical radiography using the portable and wall type dental X-ray machines. Materials and methods: Thermoluminescent chips were placed at 25 sites throughout the layers of the head and neck of a tissue-equivalent human skull phantom. The man phantom was exposed with the portable and wall type dental X-ray machines. For one periapical radiography taken by portable dental X-ray machine, the exposure setting was 60 kVp, 2 mA and 0.2 seconds, while for one periapical radiography taken by wall type dental X-ray machine, exposure setting was 70 kVp, 8 mA and 0.074 seconds. Absorbed dose measurements were performed and equivalent doses to individual organs were summed using ICRP 103 to calculate effective dose. Results: In the upper anterior periapical radiography using portable dental X-ray machine and in the lower posterior periapical radiography using both machines, the highest absorbed dose was recorded at the mandible body. The effective dose in upper anterior periapical radiography using portable and wall type dental X-ray machines was $4{\mu}Sv$, $2{\mu}Sv$, respectively. In the lower posterior periapical radiography, the effective dose for each portable and wall type dental X-ray machines was $6{\mu}Sv$, $2{\mu}Sv$. Conclusion: It was recommended that the operator use prudently potable dental X-ray machine because that the effective dose in the periapical radiography using wall type dental X-ray machine was lower than that in the periapical radiography using portable dental X-ray machine.

Utilization-Focused Reduction of Radiation Exposure with XCP-DS FIT Sensor Holder by Measuring Dose of Dental X-ray Generator (구내 방사선발생기의 선량 분포측정을 통한 필름유지기구(XCP-DS FIT)의 피폭선량감소에 대한 유용성)

  • Lee, Kyung Hee
    • 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.