• 반도체디스플레이기술학회지
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• 제9권4호
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• pp.67-70
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• 2010

X-ray absorption rate and multiplication factor of X-ray detector were calculated with Garfield code. High Z (= atomic number) was important factor to increase the absorption rate but low Z is also important to increase the multiplication. Five different gas composition were examined under the condition of 1400 V bias and 400 um gap. Xe 100% gas showed the highest absorption rate and He 96% + isobutene 4% showed the highest multiplication.

• Journal of Astronomy and Space Sciences
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• 제10권1호
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• pp.86-93
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• 1993

다중선 비례계수관에서 균일한 개스증폭도를 얻기 위한 방법에 대해 실험하였다. 양극선에 전압을 공급하는 일반적인 연결 방법으로 검출기 양쪽 끝단의 edge effect 때문에 개스증폭도의 균일성이 좋지 않았다. 따라서 전압보상법을 사용하여 개스중폭도의 균일성을 $\pm$1.6%(rms 값) 이내로 보정하였다.

• Journal of Radiation Protection and Research
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• 제30권2호
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• pp.69-75
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• 2005

기체전자증폭기(GEM, gas electron multiplier)는 동박이 양면으로 도포된 절연기관에 미세구멍배열을 형성한 박막으로 기존의 기체형 방사선 검출기의 미약한 방사선 신호를 증폭하기 위해 널리 사용되어지고 있다. 미세구멍 내부에 강한 전기장을 형성함으로써 이 내부로 유입되는 전자에 충분한 에너지를 전달, 전자사태를 유도하는 원리를 이용한다. 따라서 GEM의 특성은 GEM을 포함한 방사선 검출기에 인가되는 전압 즉, 전기장의 분포에 의해 결정된다. 따라서 올바르지 못한 전기장의 분포에 대해서는 신호 전자가 수집전극으로 향하지 못하고, GEM의 상 하단의 전극으로 이동, 신호의 손실을 초래할 수도 있다. 본 논문에서는 GEM의 가장 중요한 성능 지표 중 하나인 1차 전자수집효율(primary electron collection efficiency)을 계산하였다. 방사선에 의해 발생된 전자는 전기력선을 따라서만 움직인다는 가정 하에, GEM의 단위 구조에 대해 표류전극에서의 전기력선의 수에 대한 수집전극에서의 전기력선의 수의 비로 전자수집효율을 계산하였다. 전기력선의 계산은 3차원 유한요소법을 이용하여 계산하였다. 본 논문에서 사용한 방법은 가장 이상적인 상황으로 국한되지만, GEM의 설계 및 최적 운전변수 도출에 유용하게 사용될 수 있을 것이다.

• 대한기계학회논문집B
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• 제30권2호
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• pp.101-109
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• 2006

The narrow band-averaged transmissivity of $CO_2-H_2O$ mixtures is expressed by multiplying the transmissivities of $CO_2\;and\;H_2O$. Applying the multiplication property of narrow band transmissivities for gas mixtures of $CO_2-H_2O$ of the narrow band based WSGGM (weighted sum of gray gases model), the number of gray gases, required for accurate representation of the absorption characteristics by using the narrow band based WSGGM, is significantly increased. To reduce the computational loads by reducing the number of gray gases, we propose a gray gas regrouping process where the gray gases used for .the WSGGM are regrouped into a specified number of groups according to the magnitudes of absorption coefficients. To evaluate the proposed WSGGM for gas mixtures, the radiative transfer problems through 3-dimensional gas media are considered. The radiative source terms and the radiative heat fluxes obtained by using the proposed method are fairly well compared to previous results obtained by using the SNB model and other models. The regrouping technique results in an excellent computational efficiency with minor loss of accuracy.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.284-289
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• 2003

The narrow band-averaged transmissivity of $CO_2-H_2O$ mixtures is expressed by multiplying the transmissivities of $CO_2$ and $H_2O$. Applying the multiplication property of narrow band transmissivities for gas mixtures of $CO_2-H_2O$, the number of gray gases, required for accurate representation of the absorption characteristics by using the narrow band based WSGGM, is significantly increased. To reduce the computational loads by reducing the number of gray gases, we propose a gray gas regrouping process where the gray gases used for the WSGGM are regrouped into a specified number of groups according to the magnitudes of absorption coefficients. To evaluate the proposed WSGGM for gas mixtures, the radiative transfer problems through three-dimensional gas media are considered. The radiative source terms and the radiative heat fluxes obtained by using the proposed method are fairly well compared to those obtained by using the SNB model. The regrouping technique results in an excellent computational efficiency with minor loss of accuracy.

• 대한기계학회논문집B
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• 제27권2호
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• pp.227-235
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• 2003

The WSGG-based narrow band model was employed to solve the radiative transfer equations along isothermal and non-isothermal paths through $CO_2-H_2O-N_2$ gas mixtures at 1 atm. When the WSGGM is applied for arbitrary gas mixtures by considering the multiplication property of transmissivity in overlapping bands, the number of gray gases is significantly increased. To reduce the computation time, three different regrouping methods for the gray gases are tested in obtaining the mean absorption coefficient for each gray gas group. Among them, the regrouping method by minimizing the regrouping error shows the best results. For the isothermal media, 10 gray gases show fairly good agreement with the results by statistical narrow band(SNB) model which are regarded as reference solutions. For non-isothermal media, 20 gray gases show good agreement with reference solutions.

• 센서학회지
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• 제23권3호
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• pp.197-201
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• 2014

TEPC (Tissue Equivalent Proportional Counter) was usually used for high LET radiation dosimetry. We developed a prototype TEPC for micro-dosimetry in the range of $0.2{\sim}300 keV/{\mu}m$. And, the simulated site diameter of the TEPC is $2{\mu}m$, of similar size to a cell nucleus. For purposes of characterization the response for high LET radiation of the TEPC has been investigated under 135MeV/u Carbon ions in HIMAC (Heavy Ion Medical Accelerator). We determined the gas multiplication factor and measured the lineal energy spectrum [yd(y)] of 135 MeV/u Carbon ions. The value of the gas multiplication factor was 315 at 700 V bias voltage. As a result of the experiment, we could more understand the performance of the TEPC for high LET (Linear Energy Transfer) radiation. And the procedure of high LET radiation dosimetry using TEPC is established.

• 한국유체기계학회 논문집
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• 제19권2호
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• pp.27-35
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• 2016

The purpose of this study is to develop a method to predict the performance and economics of a micro gas turbine cogeneration system using performance correction curves. The variables of correction curves are ambient temperature, ambient pressure, relative humidity and load fraction. All of the values of correction factors were expressed as relative values with respect to design values at the ISO conditions. Once the correction curves are obtained, system performance can be predicted relatively easily compared to a detailed performance analysis method through a simple multiplication of the correction factors of various variables at any operating conditions. The predicted results using the correction curve method were compared with those by the detailed and more complex performance analysis in a wide operating range, and its feasibility was confirmed. To illustrate the usability of the correction curve method, the results of an economic analysis of a cogeneration system considering varying operating ambient condition and load was presented.

• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2725-2732
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• 2020

This paper presents the neutronics benchmark analysis of the first core of the Indonesian multipurpose research reactor RSG-GAS (Reaktor Serba Guna G.A. Siwabessy) calculated by the Serpent Monte Carlo code and the newly released ENDF/B-VIII.0 nuclear data library. RSG-GAS is a 30 MWth pool-type material testing research reactor loaded with plate-type low-enriched uranium fuel using light water as a coolant and moderator and beryllium as a reflector. Two groups of critical benchmark problems are derived on the basis of the criticality and control rod calibration experiments of the first core of RSG-GAS. The calculated results, such as the neutron effective multiplication factor (k) value and the control rod worth are compared with the experimental data. Moreover, additional calculated results, including the neutron spectra in the core, fission rate distribution, burnup calculation, sensitivity coefficients, and kinetics parameters of the first core will be compared with the previous nuclear data libraries (interlibrary comparison) such as ENDF/B-VII.1 and JENDL-4.0. The C/E values of ENDF/B-VIII.0 tend to be slightly higher compared with other nuclear data libraries. Furthermore, the neutron reaction cross-sections of ¹⁶O, ⁹Be, ²³⁵U, ²³⁸U, and S(𝛼,𝛽) of ¹H in H₂O from ENDF/B-VIII.0 have substantial updates; hence, the k sensitivities against these cross-section changes are relatively higher than other isotopes in RSG-GAS. Other important neutronics parameters such as kinetics parameters, control rod worth, and fission rate distribution are similar and consistent among the nuclear data libraries.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.206-209
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• 2003

The purpose of AR and HR coating is acquire the very low reflection rate and the high reflection rate through the deposition of a thin film using the refraction ofmaterial. Basically if the high refractive material and the low refractive material are chosen and the condition for the experiment is determined, then we solve theproject with the optical design and multi thin film coating. First of all, we choose $SiO_2$for the low refractive material and $TiO_2$ for the high refractive material and apply Sputtering System easy to control the refraction rate and excellent in reconstruction to the equipment of thin film multiplication. For the control of the refraction rate and growth rate we modify RF Power and the ratio of Gas(Ar:O2), And we use Ellipsometer for estimation and analysis of the refraction rate and growth rate and AFM&SEM for the analysis of surface and component.