• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.131-134
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• 1997

Scintillation crystals for industrial field are used in fundamental physics i.e. nuclear and high energy physics experiments besides the medical imaging, process control and gauging, container inspection, mineral process etc. For the reason of limited marketability, there are not so many studies with emphasis paced on the crystal growth. The scintillation crystal is an important theme in the studies in the fundamental physics and researchers for crystal growth are expected participate it. The present work is partly supported by a Grant-in-Aid from the Japanese Ministry of Education, Science and Culture.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05a
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• pp.213-218
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• 1997

The RTD Bypass Loops at Kori Unit 3&4 will be removed and a new system will be designed and will be installed to replace it. The replacement system provides equal or better performance and eliminates some Persistent problems. The Resistance Temperature Detector (RTD) bypass line is eliminated to reduce the radiation exposure to operators and workers. After the elimination, the resistance temperature detectors are installed in scoop of the reactor coolant piping to detect a representative temperature. This study includes safety evaluation, RTD response time Analysis, Uncertainty Analysis, LOCA evaluation and Structural Analysis.

• Electronics and Telecommunications Trends
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• v.22 no.5
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• pp.95-107
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• 2007

X-선 측정 및 영상장치를 포함한 다양한 응용분야에서 방사선에 대한 고해상도의 영상을 얻기 위한 목적으로 반도체 검출기에 대한 개발이 활발히 진행되고 있다. 본 고에서는 방사선 검출을 위해 요구되는 반도체 물질의 주요 특성에 대해서 조사하였다. 또한 반도체를 이용한 플랫 패널(flat panel) 시스템, 픽셀 디텍터(pixel detector)와 스트립 디텍터(strip detector) 등의 혼성형 디텍터(hybrid detector), MAPS와 DEPFET 등의 단일형 픽셀 디텍터(monolithic pixel detector)의 디바이스 동작 원리 및 특성과 국내외 기술 동향에 대하여 살펴보았다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.4 no.4
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• pp.34-38
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• 2005

This is a widespread requirement for low cost lightweight thermal imaging sensors for both military and civilian applications. Today, a large number of uncooled infrared detector developments are under progress due to the availability of silicon technology that enables realization of low cost IR sensor. System prices are continuing to drop, and swelling production volume will soon drive process substantially lower. The feasibility of micromechanical optical and infrared (IR) detection using microcantilevers is demonstrated. Microcantilevers provide a simple Structurefor developing single- and multi-element sensors for visible and infrared radiation that are smaller, more sensitive and lower in cost than quantum or thermal detectors. Microcantilevers coated with a heat absorbing layer undergo bending due to the differential stress originating from the bimetallic effect. This paper reports a micromachined silicon uncooled thermal imager intended for applications in automated process control. This paper presents the design, fabrication, and the behavior of cantilever for thermomechanical sensing.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.2
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• pp.112-117
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• 2008

Artifact corrections including normalization and attenuation correction were important for quantitative analysis in Nuclear Medicine Imaging. Normalization is the process of ensuring that all lines of response joining detectors in coincidence have the same effective sensitivity. Failure to account for variations in LOR sensitivity leads to bias and high-frequency artifacts in the reconstructed images. Attenuation correction is the process of the correction of attenuation phenomenon lies in the natural property that photons emitted by the radiopharmaceutical will interact with tissue and other materials as they pass through the body. In this paper, we will review the several approaches for normalization and attenuation correction strategies.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.243-248
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• 2015

We prepared semi-insulating CdTe for radiation detectors by isothermal annealing of single crystals grown by Bridgeman technique in a sealed quartz container filled with Sn vapor. The resistivity of CdTe:Sn samples thus obtained was of order of $10^{10}Ohm{\cdot}cm$ at room temperature with electrons lifetime of $2{\times}10^{-8}$ s, which is appropriate for the applications desired. Analysis of electric transport characteristics depending on temperature, sample thickness and voltage applied revealed the presence of traps with concentration of about $(4-5){\times}10^{12}cm^{-3}$ with the corresponding energy level at 0.8 - 0.9 eV counted from the bottom of conduction band. The conductivity was determined by electron injection from electrodes in space charge limited current mode.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.11
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• pp.1727-1732
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• 2004

A nickel layer was deposited onto the PZT thin films, serving both as a selective radiation absorption layer and as a top electrode. The absorption properties of such nickel coated multi-layered infrared detectors were studied in the visible and infrared wavelength ranges. The optimal thickness of the nickel layer on our substrate was 10nm. The maximum absorption coefficient of the deposited 10nm thick nickel layer was 0.7 at a 632nm wavelength. However, a striking asymmetric polarization hysteresis loop was observed in these PZT thin films with nickel as the top electrode. This asymmetric polarization was attributed to the difference between the dynamic pyroelectric responses in these Ni/PZT/Pt films poled either positively or negatively before the measurement. A positively poled film showed a 40% higher voltage response than a negatively poled detector.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2306-2312
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• 2020

Here we report on the first results of sensitivity evaluation of the gadolinium-aluminum-gallium- garnet (GAGG) scintillation detector with SiPM readout to fast and slow neutrons and, to the natural background and Co-60 γ-radiation as well. Data on sensitivity were obtained using certified dosimetry benches, so it can be utilized in the calculation of detection limits of neutron flux with such type of detectors. It was concluded that use of GAGG scintillator has a good prospect for neutron monitoring in different parts of nuclear research reactors and power plants.

• Bulletin of the Korean Space Science Society
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• 1993.10a
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• pp.11-11
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• 1993

The Korean sounding rockets(KSR) 1, 2 equigped with the UV optical detectors have been launched at An-heung, Chungchongnam-do, of June 4 and September 1, 1993,respectively. The UV detector is used to measure the attenuation of solar UV radiation for various frequency bards in the stratospgere. We obtained the profile of the ozone number density within the altitulde of 15 - 30 km by applying the Beer-Lambert law. It is found that the maHimum of the ozone distribution occurs near 2sht which is quite consistent with the mean value in the mid-latituderegions. We will also compare our results froiu KSR 1,2 with the other observational data from the Dobson speceo meter at Yonsei Univ. and the LIDAa which were performed simultaneously with the sounding rocket experiments.

• Nuclear Engineering and Technology
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• v.53 no.12
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• pp.4080-4092
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• 2021

In this study, the performance of sequence tracking methods for multiple interaction events in specific CdZnTe Compton imagers was evaluated using Monte Carlo simulations. The Compton imager consisted of a 6 × 6 array of virtual Frisch-grid CZT crystals, where the dimensions of each crystal were 5 × 5 × 12 mm³. The sequence tracking methods for another Compton imager that consists of two identical CZT crystals arrays were also evaluated. When 662 keV radiation was incident on the detectors, the percentages of the correct sequences determined by the simple comparison and deterministic methods for two sequential interactions were identical (~80%), while those evaluated using the minimum squared difference method (55-59%) and Three Compton method (45-55%) for three sequential interactions, differed from each other. The reconstructed images of a 662 keV point source detected using single and double arrays were evaluated based on their angular resolution and signal-to-noise ratio, and the results showed that the double arrays outperformed single arrays.