• Title/Summary/Keyword: 선량계측

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3-Dimensional Dosimetry of Small Field Photon Beam (광자선의 소조사면에서의 3차원적 선량 측정)

  • Jang, Ji-Sun;Kwon, Soo-Il
    • Progress in Medical Physics
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    • v.23 no.1
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    • pp.54-61
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    • 2012
  • A polymer gel dosimeter was fabricated. A 3-dimensional dosimetry experiment was performed in the small field of the photon of the cyberknife. The dosimeter was installed in a head and neck phantom. It was manufactured from the acrylic and it was used in dosimetry. By using the head and neck CT protocol of the CyberKnife system, CT images of the head and neck phantom were obtained and delivered to the treatment planning system. The irradiation to the dosimeter in the treatment planning was performed, and then, the image was obtained by using 3.0T magnetic resonance imaging (MRI) after 24 hours. The dose distribution of the phantom was analyzed by using MATLAB. The results of this measurement were compared to the results of calculation in the treatment planning. In the isodose curve on the axial direction, the dose distribution coincided with the high dose area, 0.76mm difference on 80%, rather than the low dose area, 1.29 mm difference on 40%. In this research, the fact that the polymer gel dosimeter and MRI can be applied for analyzing a small field in a 3 dimensional dosimetry was confirmed. Moreover, the feasibility of using these for the therapeutic radiation quality control was also confirmed.

Characterization of Radiation Field in the Steam Generator Water Chambers and Effective Doses to the Workers (증기발생기 수실의 방사선장 특성 및 작업자 유효선량의 평가)

  • Lee, Choon-Sik;Lee, Jai-Ki
    • Journal of Radiation Protection and Research
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    • v.24 no.4
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    • pp.215-223
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    • 1999
  • Characteristics of radiation field in the steam generator(S/G) water chamber of a PWR were investigated and the anticipated effective dose rates to the worker in the S/G chamber were evaluated by Monte Carlo simulation. The results of crud analysis in the S/G of the Kori nuclear power plant unit 1 were adopted for the source term. The MCNP4A code was used with the MIRD type anthropomorphic sex-specific mathematical phantoms for the calculation of effective doses. The radiation field intensity is dominated by downward rays, from the U-tube region, having approximate cosine distribution with respect to the polar angle. The effective dose rates to adults of nominal body size and of small body size(The phantom for a 15 year-old person was applied for this purpose) appeared to be 36.22 and 37.06 $mSvh^{-1}$) respectively, which implies that the body size effect is negligible. Meanwhile, the equivalent dose rates at three representative positions corresponding to head, chest and lower abdomen of the phantom, calculated using the estimated exposure rates, the energy spectrum and the conversion coefficients given in ICRU47, were 118, 71 and 57 $mSvh^{-1}$, respectively. This implies that the deep dose equivalent or the effective dose obtained from the personal dosimeter reading would be the over-estimate the effective dose by about two times. This justifies, with possible under- or over- response of the dosimeters to radiation of slant incidence, necessity of very careful planning and interpretation for the dosimetry of workers exposed to a non-regular radiation field of high intensity.

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Dose Evaluation of Three-Dimensional Small Animal Phantom with Film Dosimetry (필름계측을 이용한 3차원 소동물 팬텀의 선량평가)

  • Han, Su Chul;Park, Seungwoo
    • Journal of radiological science and technology
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    • v.40 no.1
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    • pp.87-92
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    • 2017
  • The weight of small animal dosimetry has been continuously increased in pre-clinical studies using radiation in small animals. In this study, three-dimensional(3D) small animal phantom was fabricated using 3D printer which has been continuously used and studied in the various fields. The absorbed dose of 3D animal phantom was evaluated by film dosimetry. Previously, the response of film was obtained from the materials used for production of 3D small animal phantom and compared with the bolus used as the tissue equivalent material in the radiotherapy. When irradiated with gamma rays from 0.5 Gy to 6 Gy, it was confirmed that there was a small difference of less than 1% except 0.5 Gy dose. And when small animal phantom was irradiated with 5 Gy, the difference between the irradiated dose and calculated dose from film was within 2%. Based on this study, it would be possible to increase the reliability of dose in pre-clinical studies using irradiation in small animals by evaluating dose of 3D small animal phantom.

A Research of Domestic Radiation Measurement Devices Suitable for Use in the Event of a Radioactive Disaster (방사능재난 시 주민이 사용하기 적합한 국내 방사선 계측기에 대한 조사)

  • Park, Nam-Hee;Sim, Da-Som
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2023.11a
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    • pp.224-225
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    • 2023
  • 방사능재난 시 주민의 방사선 피폭을 최소화하기 위하여 대피 및 소개가 신속하게 이루어져야 한다. 주민이 휴대용 방사선 계측기를 통하여 방사능 오염 발생을 감지해 사전에 신속히 대피할 수 있다면, 방사능재난 대응에 기여할 수 있을 것으로 사료된다. 본 논문에서는 방사능재난 시 주민이 사용하기 용이한 방사선 계측기를 제시하고, 향후 보완하여야 하는 사항에 대해 검토하였다.

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A Study on the Measurement Linearity of Photoluminescent Dosimeter (형광유리선량계의 계측 직선성 연구)

  • Jeong, Kyeong-Hwan;Jung, Dong-Kyung;Seo, Jeong-Min
    • Journal of the Korean Society of Radiology
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    • v.15 no.6
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    • pp.841-847
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    • 2021
  • Related institutions that use radiation are diverse in Korea, such as research, medical care, and education. Recently, the number of examinations and visits to medical institutions is increasing. As a result, the number of radiological examinations in medical institutions is increasing. Radiation safety management is necessary as well as exposure of radiation workers. For safety management, first of all, it is necessary to wear the personal exposure dosimeter correctly and measure it accurately after wearing it. This study tries to evaluate and verify the measurement straightness of PLD devices by radiation of a diagnostic generator. Radiation division irradiation time interval was measured after irradiating 10 times at 10, 30, and 60 sec and irradiating the irradiation distance from 30 to 100 cm at 10 cm intervals to measure the change in absorbed dose depending on the distance. As a result, there was no difference in absorbed dose by time interval. This is considered to be helpful in various studies by using a diagnostic generator for the study of high absorbed dose.