• Journal of radiological science and technology
• /
• v.38 no.2
• /
• pp.101-106
• /
• 2015

Recently, There has been a growing interests in exposure dose to the patient who take a examination using radiation. The radiological technologists should be concerned about the exposure dose to patients and make an efforts to reduce the patient dose without decreasing the image quality. In the case of foreign, the exposure dose of general X-ray examination have been managed by standard value of exposure dose using dose area product (DAP) and entrance surface dose (ESD) dosimeter. This study is to compare DAP and ESD in skull anterior posterior (AP), chest posterior anterior (PA), and abdomen AP projections of phantom by using DAP and ESD dosimeter. In the results, there were no differences between DAP and ESD dosimeter.

• Journal of the Korean Society of Radiology
• /
• v.12 no.2
• /
• pp.149-157
• /
• 2018

One of the purposes of radiation protection is to minimize stochastic effects. PCXMC 2.0 is a Monte Carlo Simulation based program and makes it possible to predict effective dose and the probability of cancer development through entrance surface dose. Therefore, it is especially important to measure entrance surface dose through dosimeter. The purpose of this study is to measure entrance surface dose through semiconductor dosimeter, general dosimeter, glass dosimeter, and to compare and analyze the effective dose and probability of disease of critical organs. As an experimental method, the entrance surface dose of skull, chest, abdomen was measured per dosimeter and the effective dose and the probability of cancer development of critical organs per area was evaluated by PCXMC 2.0. As a result, the entrance surface dose per area was different in the order of a general dosimeter, a semiconductor dosimeter, and a glass dosimeter even under the same condition. Base on this analysis, the effective dose and probability of developing cancer of critical organs were also different in the order of a general dosimeter, a semiconductor dosimeter, and a glass dosimeter. In conclusion, it was found that the effective dose and the risk of diseases differ according to the dosimeter used, even under the same conditions, and through this study it was found that it is important to present an accurate entrance surface dose model according to each dosimeter.

• Journal of radiological science and technology
• /
• v.42 no.6
• /
• pp.483-489
• /
• 2019

This paper obtained and compared these dose values by setting and comparing the X-ray imaging conditions (tube voltage 60 kVp, 70 kVp, 80 kVp, tube current 10 mAs, 16 mAs and X-ray field size are 10 × 10 cm, 15 × 15 cm). Each dose value was measure 10 times and represented as an average value. The purpose of this experiment is to serve as a reference for the X-ray exposure of diagnostic areas according to the type of dosimeter and to help with another dose measurement. The results of the experiment showed very little difference between the glass dosimeter(GD) and semiconductor dosimeter values due to changes in tube voltage of 60, 70, 80 kVp, regardless of field sized, but for dose area product(DAP), the difference in dose value was significant according to field size.

• Journal of Radiation Protection and Research
• /
• v.27 no.1
• /
• pp.51-57
• /
• 2002

An electronic personal dosimeter(EPD) with hybrid type preamplifier adopting a semiconductor detector as a radiation detector has been developed, manufactured and test-evaluated. The radiation detection characteristics of this EPD has been performance-tested by using a reference photon radiation field. After several test-irradiations to a $^{137}Cs$ gamma radiation source the radiation detection sensitivity of this EPD appeared to be $3.8\;cps/Gy{\cdot}h^{-1}$. The linearity of radiation response was kept within 8% of the dose equivalent ranges of $10{\mu}Sv{\sim}4Sv$ and the angular dependence was under less than 4% in angles of ${\pm}60^{\circ}$. It was confirmed that the energy response range was in $60{\sim}1,250keV$ given in the ISO standard. This EPD satisfied the international criteria for the EPD in the mechanical and the environmental performance test for 9 test categories according to IEC 61526.

• Journal of the Korean Society of Radiology
• /
• v.14 no.1
• /
• pp.1-6
• /
• 2020

In this study, it was intended to replace the existing plane parallel ionization chamber, which requires cross-calibration in electron beam treatment. The semiconductor compounds HgI₂ was fabricated as detector, and the characteristics of HgI₂ detector for the 6, 9 and 12 MeV electron beam was analyzed in the linear accelerator. It was also intended to evaluate the possibility of substitution with existing detectors and their applicability as electron beam dosimetry and to use them as a basic study of the development of electronic beam dosimeter. As a result of reproducibility, RSD was 0.4246%, 0.5054%, and 0.8640% at 6, 9, and 12 MeV energy, respectively, indicating that the output signal was stable. As a result of the linearity, the R² was 0.9999 at 6 MeV, 0.9996 at 9 MeV, and 0.9997 at 12 MeV showed that the output signal is proportional to HgI₂ as the dose is increased. The HgI₂ detector of this study is highly applicable to electron beam measurement, and it may be used as a basic research on electron beam detection.

• The Journal of Korean Society for Radiation Therapy
• /
• v.17 no.1
• /
• pp.57-71
• /
• 2005

Purpose : To evaluate radiation dose and accuracy with TLD and diode detector when treat total skin with electron beam. Materials and Methods : Using Stanford Technique, we treated patient with Mycosis Fungoides. 6 MeV electron beam of LINAC was used and the SSD was 300 cm. Also, acrylic speller(0.8 cm) was used. The patient position was 6 types and the gantry angle was 64, 90 and $116^{\circ}$. The patient's skin dose and the output were detected 5 to 6 times with TLD and diode. Result : The deviations of dose detected with TLD from tumor dose were CA $+\;6\%$, thigh $+\;8\%$, umbilicus $+\;4\%$, calf $-\;8\%$, vertex $-\;74.4\%$, deep axillae $-\;10.2\%$, anus and testis $-\;87\%$, sole $-\;86\%$ and nails shielded with 4mm lead $+4\%$. The deviations of dose detected with diode were $-4.5\%{\sim}+5\%$ at the patient center and $-1.1\%{\sim}+1\%$ at the speller. Conclusion : The deviation of total skin dose was $+\;8\%{\sim}-\;8\%$ and that deviation was within the acceptable range(${\pm}\;10\%$). The boost dose was irradiated for the low dose areas(vertex, anus, sole). The electron beam output detected at the sootier was stable. It is thought that the deviation of dose at patient center detected with diode was induced by detection point and patient position.

• 대한방사선치료학회:학술대회논문집
• /
• 2004.03a
• /
• pp.9-9
• /
• 2004

• Journal of Sensor Science and Technology
• /
• v.9 no.4
• /
• pp.274-280
• /
• 2000

This paper deals with an experimental study to apply commercial semiconductors to measure radiation dose rate for gamma ray. Since the low cost, small size, high efficiency and ruggedness of silicon photodiodes make them attractive photodetectors, they coulde be effectively used in measuring any radiation such as gamma ray. Most PN photodiodes show that the reverse current increases when the light is increased. Therefore the depletion region of them have influence on the reverse current, so we choose silicon PIN photodiodes with large depletion region. In order to detect radiation dose rate and then, to apply in developing any gamma ray dosimeter, some examinations and experiments were performed to PIN photodiodes in this work. Two kinds of PIN photodiodes, such as NEC's PH302 and SIEMENS's BPW34, were tested in a Co-60 gamma irradiation facility with a semiconductor parameter analyzer. As a result, we found that such PIN photodiodes present good linearity in diode current characteristics with dose rate. Therefore silicon PIN photodiodes could be suitably used in designing gamma ray dosimeters.

• Journal of the Korean Society of Radiology
• /
• v.11 no.1
• /
• pp.37-42
• /
• 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.

• Proceedings of the KIEE Conference
• /
• 2004.07d
• /
• pp.2353-2355
• /
• 2004

본 논문에서는 고정도의 방사선 측정이 가능한 능동형 전자선량계를 제작하기 위해 필수적으로 요구되는 반도체 방사선 검출기를 ASIC으로 구현하였다. 이는 전자선량계의 소형화와 저소비전력을 실현할 수 있도록 전치증폭기와 성형증폭기를 일체화한 것으로 방사선과 방사선 검출 소자인 상용 핀 포토다이오드의 상호작용으로 생성된 수 [nA]의 전류펄스를 측정할 수 있다. MOSIS 공정을 통하여 ASIC으로 구현된 방사선검출기는 $10{\mu}Ci$의 ${\gamma}$-선 Ba-133, Cs-137 및 Co-60의 세 핵종에 대하여 방사선 조사시험을 수행하여 구현된 방사선 검출기의 유용성을 입증하였다.