• 한국진공학회지
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• 제7권1호
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• pp.1-4
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• 1998

이온 펌프의 중심에 네그(Non-Evaporable Getters)가 삽입된 새로운 조합 펌프를 사용하여 극고진공 시스템을 구현하였다. 진공 용기는 터보 분자 펌프만으로도 극고진공에 성공하였던, $450^{\circ}C$에서 잘 산화된 304 스테인레스 스틸 쳄버를 사용하였다. 시스템의 압력은 Leybold사의 EXG(Extractor Gauge)로 측정하였으나, 본 실험에서의 최고 진공도는 이미 그 게이지의 측정 한계인 1~$2\times10^{-12}$torr범위를 훨씬 지나 게이지 지시가 $-0\times10^{-12}$torr를 읽교 있는 극고진공에 도달해 있었다. 이는 효과적인 네그 활성화로 수소 가스에 대한 배기 속도 를 크게 향상시켜준 결과라 볼 수 있다. 또한 본 실험은 극고진공 표면 분석 장치의 실현 가능성을 시사해주는 것으로, 앞으로의 초미세 표면 과학에 있어서 새로운 장을 열어줄 것 으로 기대된다.

• 한국진공학회지
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• 제18권4호
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• pp.272-280
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• 2009

원판형 분자 드래그펌프 내부의 회전자 위치에 따른 압축 성능과 배기특성에 대하여 실험과 수치 해석적으로 고찰하였다. 실험은 각각의 회전자 위치에 진공압력 게이지들을 부착하여, 펌프의 출구 압력이 0.2 Pa에서 533 Pa 사이일 때, 각 회전자에서의 압력을 측정하였다. 압력측정범위는 출구 압력이 0.2 Pa에서 533 Pa 범위사이에서 측정하였다. 진공펌프 로터의 회전 속도는 24,000 rpm이며, 질소 가스를 사용하여 성능실험을 수행하였다. 본 연구에서는 원판의 단의 수에 따른 원판형 분자 드래그펌프의 성능특성을 파악하고자 하였다. 수치해석을 통해 내부 유동채널에 대한 구체적인 압력 분포를 파악하였으며, 수치해석의 신뢰도 파악을 위하여 실험 측정값과 수치해석 값을 비교하여 검증하였다.

• Applied Science and Convergence Technology
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• 제23권2호
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• pp.97-102
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• 2014

A vacuum chamber for a commercial atomic force microscope (AFM) is designed and fabricated. Only minimal modifications were made to an existing microscope in an effort to work in a vacuum environment, while most of the available AFM functionalities were kept intact. The optical alignment needed for proper AFM operations including a SLD (superluminescent diode) and a photodiode can be made externally without breaking the vacuum. A vacuum level of $5{\times}10^{-3}$ torr was achieved with a mechanical pump. An enhancement of the quality factor was observed along with a shift in the resonance frequency of a non-contact-mode cantilever in a vacuum. Topographical data of a calibration sample were also obtained in air and in a low vacuum using the non-contact mode and the results were compared.

• International journal of advanced smart convergence
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• 제10권1호
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• pp.159-165
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• 2021

Electronic devices used in the mobile environments fabricated under the plasma conditions in high vacuum system. Especially for the development of advanced electronic devices, high quality plasma as the process conditions are required. For this purpose, the variable conductance throttle valves for controllable plasma employed to the high vacuum system. In this study, we analyzed the effects of throttle valve applications on vacuum characteristics simulated to obtain the optimum design modelling for plasma conditions of high vacuum system. We used commercial simulator of vacuum system, VacSim(multi) on this study. Reliability of simulator verified by simulation of the commercially available models of high vacuum system. Simulated vacuum characteristics of the proposed modelling agreed with the observed experimental behaviour of real systems. Pressure limit valve and normally on-off control valve schematized as the modelling of throttle valve for the constant process-pressure of below 10-3 torr. Simulation results plotted as pump down curve of chamber, variable valve conductance and conductance logic of throttle valve. Simulated behaviors showed the applications of throttle valve sustained the process-pressure constantly, stably, and reliably in plasma process.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.416-422
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• 2007

The application analysis of bubble pump on the domestic solar water heater system is presented. The system investigated in this study is a passive device, self pumping and self regulating. It was test to use the bubble pump on solar water heater system. The test experiment has been taken on the existed vacuum tube about the efficiency, working fluid temperature and pressure and circulated power. In order to check the working temperature and working pressure effectively, the bubble pump was test separated from the solar water heater. The equipment consists of the bubble pump, heater and heat exchanger. The main structure of bubble pump was design depend on the character of two phase flow. The complete system was instrumented to measure pressures, temperatures and their relationship with the solar radiation intensity. The theory analysis of design bubble pump has been given and the experiment result analysis has been included in the paper.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.217-223
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• 2023

In this study, we compared the VacCAD and VacTran, commercial vacuum simulators, to investigate the simulation applicability and efficiency as vacuum simulation software. It was verified on reliability and simplicity of simulation modelling, and characteristics of the pump combinations, pumping down curves, and employed vacuum materials. First, usability of simulation schematics was estimated through the modeling tools and the overall simulation characteristics of each simulator were compared to evaluate the applicability in practice. Simulation reliability of each simulator was also probed by comparing the pumping performance characteristics of commercial high vacuum system models. In addition, the degree of tolerances on both simulators was also evaluated through pumping down analysis considering outgassing effect due to chamber material variations. The higher effectiveness and expediency of VacCAD than VacTran has been presented, and it was also expected that the utilization of VacTan in vacuum applications to be increased due to the higher availability of modelling variations.

• 한국진공학회지
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• 제20권3호
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• pp.165-175
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• 2011

본 논문에서는 건식 진공펌프에서 측정한 다중 변수로 구성된 배치데이터의 통계적인 특성을 소개한다. 흡입구 및 배출구 압력과 부스터/드라이 펌프의 소비전류와 같은 상태변수의 변위분포는 2개나 3개의 특정적인 구간으로 나뉘는 특성이 있다. 이런 관측을 통해 발견한 통계학적 특성을 나타내기 위해 적응형 인자 모델(APM)을 사용하였다. APM 모델기반의 배치 데이터는 건식 진공펌프의 상태를 진단하는데 적절함을 증명하였고, 이전의 동적 시간 왜곡 알고리즘과 비교하였을 때 계산시간 및 필요 메모리 면에서 효율적임을 확인하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2309-2314
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• 2007

The application analysis of bubble pump on the domestic solar water heater system is presented. The system investigated in this study is a passive device, self pumping and self regulating. It was test to use the bubble pump on solar water heater system. The test experiment has been taken on the existed vacuum tube about the efficiency, working fluid temperature and pressure and circulated power. In order to check the working temperature and working pressure effectively, the bubble pump was test separated from the solar water heater. The equipment consists of the bubble pump, heater and heat exchanger. The main structure of bubble pump was design depend on the character of two phase flow. The complete system was instrumented to measure pressures, temperatures and flow-rates at various locations. The theory analysis of design bubble pump has been given and the experiment design has been included in the paper.

• 설비공학논문집
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• 제8권2호
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• pp.219-229
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• 1996

In the free molecular flow range, the pumping performance of a turbomolecular pump has been predicted by calculation of the transmission probability employing the integral method and the test particle Monte-Carlo method. The velocities of molecules incident upon a moving blade are given by the random numbers, which are sampled from the Maxwell molecular velocity distribution function. The present results agree quantitatively with the previous known numerical results. For a multi-stage pump, the velocity profile of molecules between two blade rows is not Maxwell distribution. In this case, the Monte-Carlo method is employed to calculate the overall transmission probability for the entire set of blade rows. When the results of the approximate method combining the single stage solutions are compared with those of the Monte-Carlo method for the pump having six rows at C=0.6, the approximate method overestimates as much as 36% in the maximum compression ratio and 19% in the maximum pumping speed than does the Mote-Carlo method.

• International journal of advanced smart convergence
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• 제8권4호
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• pp.200-206
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• 2019

In this study, we compared the VacCAD and VacSim^(Multi), commercial vacuum simulators, to verify the advantages of VacCAD's efficiency. It was emphasized on immediacy and simplicity of simulation modelling, and characteristics of the pump combinations, pumping down curves, and vacuum materials. First, usability of simulation mechanism was estimated through the modeling schematics and obtained simulation results of each employed simulator were compared to evaluate the applicability in practice. Simulation reliability of each simulator was also probed by comparing the pumping characteristics of commercially available high vacuum systems. In addition, the degree of tolerances on VacCAD was also investigated through pumping down analysis considering outgassing effect due to chamber material variations. The higher effectiveness and expediency of VacCAD than VacSim^(Multi) has been presented, and it was expected that the utilization of VacCAD in vacuum applications to be increased.