• Title/Summary/Keyword: 개인선량

Search Result 215, Processing Time 0.023 seconds

A Study on Development of a PIN Semiconductor Detector for Measuring Individual Dose (개인 선량 측정용 PIN 반도체 검출기 개발에 관한 연구)

  • Lee, B.J.;Lee, W.N.;Khang, B.O.;Chang, S.Y.;Rho, S.R.;Chae, H.S.
    • Journal of Radiation Protection and Research
    • /
    • v.28 no.2
    • /
    • pp.87-95
    • /
    • 2003
  • The fabrication process and the structure of PIN semiconductor detectors have been designed optimally by simulation for doping concentration and width of p+ layer, impurities re-contribution due to annealing and the current distribution due to guard ring at the sliced edges. The characteristics to radiation response has been also simulated in terms of Monte Carlo Method. The device has been fabricated on n type, $400\;{\Omega}cm$, orientation <100>, Floating-Zone silicon wafer using the simulation results. The leakage current density of $0.7nA/cm^2/100{\mu}m$ is achieved by this process. The good linearity of radiation response to Cs-137 was kept within the exposure ranges between 5 mR/h and 25 R/h. This proposed process could be applied for fabricating a PIN semiconductor detector for measuring individual dose.

A Study on the Food Consumption Rates for Off-site Radiological Dose Assessment around Korean Nuclear Power Plants (국내 원자력발전소 주변 주민의 방사선량 평가를 위한 음식물 섭취율 설정 연구)

  • Lee, Gab-Bock;Chung, Yang-Geun
    • Journal of Radiation Protection and Research
    • /
    • v.33 no.4
    • /
    • pp.183-196
    • /
    • 2008
  • The internal dose by food consumption mostly accounts for radiological dose of public around nuclear power plants (NPPs). But, food consumption rates applied to off-site dose calculation in Korea which are the result of field investigation around Kori NPP by the KAERI (Korea Atomic Energy Research Institute) in 1988, are not able to reflect the latest dietary characteristics of Korean. The food consumption rates to be used for radiological dose assessment in Korea are based on the maximum individual of US NRC (Nuclear Regulatory Commssion) Regulatory Guide 1.109. However, the representative individual of the critical group is considered in the recent ICRP (International Commission on Radiological Protection) recommendation and European nations' practice. Therefore, the study on the re-establishment of the food consumption rates for individual around nuclear power plant sites in Korea was carried out to reflect on the recent change of the Korean dietary characteristics and to apply the representative individual of critical group to domestic regulations. The Ministry of Health and Welfare Affairs has investigated the food and nutrition of nations every 3 years based on the Law of National Health Improvement. The statistical data such as mean, standard deviation, various percentile values about food consumption rates to be used for the representative individual of the critical group were analyzed by using the raw data of the national food consumption survey in $2001{\sim}2002$. Also, the food consumption rates for maximum individual are re-estimated.

Application of the Two-Dosimeter Algorithm for Effective Dose Evaluations based on ICRP Publication 103 (ICRP 103 방사선방호 체계 하에서 유효선량 평가를 위한 Two-Dosimeter Algorithm의 적용방안)

  • Kim, Hee-Geun;Kong, Tae-Young
    • Journal of Radiation Protection and Research
    • /
    • v.36 no.3
    • /
    • pp.154-159
    • /
    • 2011
  • To evaluate the radiation exposure of workers participating in task where high radiation exposure is expected, two-dosimeter is typically provided radiation workers, one on the chest and the other on the back, at Korean nuclear power plants (NPPs). In a previous study, the NCRP (55:50) algorithm was selected as the optimal two-dosimeter algorithm (TDA) with various field tests and this TDA has been applied to all Korean NPPs since 2006. In 2007, the International Commission on Radiological Protection (ICRP) published the new ICRP recommendation, ICRP 103, which provides the revised weighting factors for both radiation and tissues and the new reference phantom. In this study, the applicability of current NCRP (55:50) algorithm at Korean NPPs for ICRP 103 was analyzed. As a result, it was found that the NCRP (55:50) algorithm is still effective to estimate the effective dose of workers under ICRP 103.

Developments of Space Radiation Dosimeter using Commercial Si Radiation Sensor (범용 실리콘 방사선 센서를 이용한 우주방사선 선량계 개발)

  • Jong-kyu Cheon;Sunghwan Kim
    • Journal of the Korean Society of Radiology
    • /
    • v.17 no.3
    • /
    • pp.367-373
    • /
    • 2023
  • Aircrews and passengers are exposed to radiation from cosmic rays and secondary scattered rays generated by reactions with air or aircraft. For aircrews, radiation safety management is based on the exposure dose calculated using a space-weather environment simulation. However, the exposure dose varies depending on solar activity, altitude, flight path, etc., so measuring by route is more suggestive than the calculation. In this study, we developed an instrument to measure the cosmic radiation dose using a general-purpose Si sensor and a multichannel analyzer. The dose calculation applied the algorithm of CRaTER (Cosmic Ray Telescope for the Effects of Radiation), a space radiation measuring device of NASA. Energy and dose calibration was performed with Cs-137 662 keV gamma rays at a standard calibration facility, and good dose rate dependence was confirmed in the experimental range. Using the instrument, the dose was directly measured on the international line between Dubai and Incheon in May 2023, and it was similar to the result calculated by KREAM (Korean Radiation Exposure Assessment Model for Aviation Route Dose) within 12%. It was confirmed that the dose increased as the altitude and latitude increased, consistent with the calculation results by KREAM. Some limitations require more verification experiments. However, we confirmed it has sufficient utilization potential as a cost-effective measuring instrument for monitoring exposure dose inside or on personal aircraft.

Development of Dose Planning System for Brachytherapy with High Dose Rate Using Ir-192 Source (고선량률 강내조사선원을 이용한 근접조사선량계획전산화 개발)

  • Choi Tae Jin;Yei Ji Won;Kim Jin Hee;Kim OK;Lee Ho Joon;Han Hyun Soo
    • Radiation Oncology Journal
    • /
    • v.20 no.3
    • /
    • pp.283-293
    • /
    • 2002
  • Purpose : A PC based brachytherapy planning system was developed to display dose distributions on simulation images by 2D isodose curve including the dose profiles, dose-volume histogram and 30 dose distributions. Materials and Methods : Brachytherapy dose planning software was developed especially for the Ir-192 source, which had been developed by KAERI as a substitute for the Co-60 source. The dose computation was achieved by searching for a pre-computed dose matrix which was tabulated as a function of radial and axial distance from a source. In the computation process, the effects of the tissue scattering correction factor and anisotropic dose distributions were included. The computed dose distributions were displayed in 2D film image including the profile dose, 3D isodose curves with wire frame forms and dosevolume histogram. Results : The brachytherapy dose plan was initiated by obtaining source positions on the principal plane of the source axis. The dose distributions in tissue were computed on a $200\times200\;(mm^2)$ plane on which the source axis was located at the center of the plane. The point doses along the longitudinal axis of the source were $4.5\~9.0\%$ smaller than those on the radial axis of the plane, due to the anisotropy created by the cylindrical shape of the source. When compared to manual calculation, the point doses showed $1\~5\%$ discrepancies from the benchmarking plan. The 2D dose distributions of different planes were matched to the same administered isodose level in order to analyze the shape of the optimized dose level. The accumulated dose-volume histogram, displayed as a function of the percentage volume of administered minimum dose level, was used to guide the volume analysis. Conclusion : This study evaluated the developed computerized dose planning system of brachytherapy. The dose distribution was displayed on the coronal, sagittal and axial planes with the dose histogram. The accumulated DVH and 3D dose distributions provided by the developed system may be useful tools for dose analysis in comparison with orthogonal dose planning.

Comparison on the Dosimetry of TLD and PLD by Dose Area Product (DAP(Dose Area Product)를 이용한 TLD와 PLD의 선량 측정 비교)

  • Choi, Jae-Ho;Kang, Gu-Jun;Chang, Seo-Goo
    • The Journal of the Korea Contents Association
    • /
    • v.12 no.3
    • /
    • pp.244-250
    • /
    • 2012
  • The results of analyzing the difference between performances of individual dosimeters on this research subjecting the PLD and TLD, which are the official personal dosimeters, through dosimetry are as follows. After scanning the integral dose using an automatic scanner, the values of two devices that went through dose adjustment process had a statistical difference in TLD and PLD measurements under each filming conditions which were 70kVp, 200mA, 0.012sec and 42kVp, 100mA, and 0.012sec (p<0.001 and p<0.001 respectively). As for the difference of measurement value between DAP and the two particles under 70kVp, 200mA, 0.012sec filming condition, TLD had a value lower than DAP average value by $44.2mGy{\cdot}cm^2$ and PLD had a value of $246.8mGy{\cdot}cm^2$ which was lower than DAP average value by $15.5mGy{\cdot}cm^2$, while under 42kVp, 100mA, 0.012sec filming condition, TLD had a value lower than DAP average value by $17.9mGy{\cdot}cm^2$ and PLD had a value of $82.6mGy{\cdot}cm^2$ which was lower than DAP average value by 7.6$mGy{\cdot}cm^2$. Also, compared to PLD, each of 10 devices measured dose value in TLD had a larger deviation between the particles, and for a reproducibility test which repeatedly measured one particle, PLD had ${\pm}1%$ which was lower than TLD's ${\pm}2%$. As such, PLD had a superior performance result in dose measurement capacities aspect compared to TLD, and therefore we could verify that PLD is more appropriate and advantageous in managing radiation-related task performing worker's personal radiation exposure management in the diagnostic radiation field.

Study on The Planning and Operation of Training Education in Radiologic Science for Reduced x-ray Exposure (방사선(학)과 실습교육에서 X선 피폭 감소를 위한 운영방법에 대한 연구)

  • Kil, Jong-Won;Park, Jung-Ho;Kim, Yong-Gwon
    • Journal of the Institute of Electronics and Information Engineers
    • /
    • v.51 no.12
    • /
    • pp.174-179
    • /
    • 2014
  • In this study, we measure the radiation dose for every experiments performed during the training education in radiologic science and estimate the radiation dose to each participant in the training education to propose a safe curriculum including operation of the training education. In this paper, we optimized the three parameters and the results show the dramatically reduced radiation dose to each participant. The proposed arrangement of the subjects and operation of the training education will be very helpful to reorganize the curriculum and the subject operation and will protect the students from the radiation dose.

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
    • /
    • v.15 no.6
    • /
    • pp.841-847
    • /
    • 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.

A Study on the Environmental Radiation Dose Measurement in the Nuclear Medicine Department (핵의학과에서 환경방사선량 측정에 대한 연구)

  • Kang, Bo-Sun;Lim, Chang-Seon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.11 no.6
    • /
    • pp.2118-2123
    • /
    • 2010
  • Korean individual occupational exposure control is focused on the retrospective service to the over-exposed person by the reading of personal dosimeter. Since the radiophamaceuticals using in the nuclear medicine department are uncontained radiation sources, the potential exposure at working environment is very high. Moreover, a patient remains radioactive for hours or even days after the administration of a radiopharmaceutical for diagnosis or treatment. Thus, the proper working environmental exposure control must be established and executed to protect not only the affiliated employees, but also guardians accompanying patients and temporarily visiting public from the exposure by the patients. Japanese radiation protection law regulates working environmental radiation exposure by regularly measuring and filing the environmental dose for years. This study was aimed at measuring working environmental radiation dose in the nuclear medicine department of an university hospital located in Daejeon, Korea. We measured the accumulation radiation dose in air at 8 locations in the nuclear medicine department by using the same method as in Japan with glass dosimeters. The highest dose rate, 0.23 mSv per month, was measured at the waiting room, and the second one is at reception desk. Even though the doses were lower than the Korean constraint dose rate (0.3 mSv/week) at the boundary of the radiation controlled area, it was over the dose limit of public (1 mSv/y) and environment (0.25 mSv/y). Conclusionally, it was found that the new or additional procedure was necessary to less the exposure dose to the receptionist and guardians by the environmental radiation dose in the nuclear medicine department.

A Study on Characteristic of Glass Dosimeter According to Graded Change of Tube Current (유리선량계의 단계별 관전류량 변화에 따른 특성연구)

  • Son, Jin-Hyun;Kim, Seong-Ho;Mun, Hyun-Jun;Kim, Lyun-Kyun;Son, In-Hwa;Kim, Young-Jun;Min, Jung-Whan;Kim, Ki-Won
    • Journal of radiological science and technology
    • /
    • v.37 no.2
    • /
    • pp.135-141
    • /
    • 2014
  • This study was evaluated the linearity and reproducibility according to dose, and reproducibility according to delay time by changing tube current amount (5 mAs, 10 mAs, 16 mAs, 20 mAs, 25 mAs, 32 mAs respectively, which are low energy radiations) using Glass Dosimeter (GD) and piranha semiconductor dosimeter which are used for measuring exposure dose. Measurements of radiation dose were performed using external detector of piranha 657 which is multi-function QA device (RTI Electronic, Sweden). Conditions of measurement were 80 kVp, SSD 100 cm and exposure region is $10cm{\times}10cm$. Glass dosimeter was exposed to radiation. Twenty-four glass dosimeters were divided into six groups (5 mAs, 10 mAs, 16 mAs, 20 mAs, 25 mAs, 32 mAs respectively), then measured. This study was resulted by measuring the linearity and reproducibility according to change of tube current in low energy field. In dose characteristic of GD, this study could be useful as previous study with regard to dose characteristic according to change of tube voltage in low energy field.