• Title/Summary/Keyword: Linear ion source

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Comparison the reference ion chamber in using the radioactive check source and field ion chamber for output dose for Co-60 source of remote afterloading system (시험선원을 이용한 기준 전리함의 감도변화와 임상필드전리함의 성능 안정성 비교)

  • 최태진
    • Progress in Medical Physics
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    • v.12 no.2
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    • pp.141-146
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    • 2001
  • It is well known that assurance of the radiation therapy needs for an accuracy of $\pm$ 5 % in the delivery of an absorbed dose to target volume. Therefore, the dose evaluation of brachytherapy source and/or linear accelerate beam must be a stability with accuracy. In an advanced country, they recommended to use the radioactive check source for reference air ionization chamber for a stable response of radiation field chamber. In this experiments, the radioactive source Sr-90 and PR-05 air ionization chamber were used for standard source and reference ion chamber. The response of reference ion chamber showed as an 1.000$\pm$ 0.010 uncertainty for 10 years long and the evaliuation f dose discrepancy of clinical field ion chamber showed as 0.997 $\pm$0.011 in a $^{60}$ Co brachytherapy soruce. In our experiments, we can assuarance the long halflife standard source is reliable to preserve the calibration factor of reference chamber in stability.

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Improvement of Adhesion Strength of DLC Films on Nitrided Layer Prepared by Linear Ion Source

  • Shin, Chang-Seouk;Kim, Wang-Ryeol;Park, Min-Seok;Jung, Uoo-Chang;Chung, Won-Sub
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.177-179
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    • 2011
  • The purpose of this study is to enhance an adhesion between substrate and Diamond-like Carbon (DLC) film. DLC has many outstanding properties such as low friction, high wear resistance and corrosion resistance. However, it is difficult to achieve enough adhesion because of weak bonding between DLC film and the substrate. For improvement adhesion, a layer between DLC film and the substrate was prepared by dual post plasma. DLC film was deposited on nitrided layer by linear ion source. The composed compound layer between substrate and DLC film was investigated by Glow Discharge Spectrometer (GDS) and Scanning Electron Microscope (SEM). The synthesized bonding structure of DLC film was analyzed using a micro raman spectrometer. Mechanical properties were measured by nano-indentation. In order to clarify the mechanism for improvement in adhesive strength, it was observed by scratch test.

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Coatings Properties and Efficiency Performance of Cr-DLC Films Deposited by Hybrid Linear Ion Source for Hydraulic Gear Pump (하이브리드 선형이온원에 의한 유압 기어펌프용 Cr-DLC코팅막의 특성과 효율성능)

  • Cha, Sun-Yong;Kim, Wang-Ryeol;Park, Min-Suk;Kwon, Se-Hun;Chung, Won-Sub;Kang, Myung-Chang
    • Journal of Powder Materials
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    • v.17 no.6
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    • pp.456-463
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    • 2010
  • This paper describes the results of the application of Cr-Diamond-like carbon (DLC) films for efficiency improvement through surface modification of spur gear parts in the hydraulic gear pump. Cr-DLC films were successfully deposited on SCM 415 substrates by a hybrid coating process using linear ion source (LIS) and magnetron sputtering method. The characteristics of the films were systematically investigated using FE-SEM, nano-indentation, sliding tester and AFM instrument. The microstructure of Cr-DLC films turned into the dense and fine grains with relatively preferred orientation. The thickness formed in our Cr buffer layer and DLC coating layer were obtained the 487 nm and $1.14\;{\mu}m$. The average friction coefficient of Cr-DLC films considerably decreased to 0.15 for 0.50 of uncoated SCM415 material. The hardness and surface roughness of Cr-DLC films were measured 20 GPa and 10.76 nm, respectively. And then, efficiency tests were performed on the hydraulic gear pump to investigate the efficiency performance of the Cr-DLC coated spur gear. The experimental results show that the volumetric and mechanical efficiency of hydraulic gear pump using the Cr-DLC spur gear were improved up to 2~5% and better efficiency improvement could be attributed to its excellent microstructure, higher hardness, and lower friction coefficient. This conclusion proves the feasibility in the efficiency improvement of hydraulic gear pump for industrial applications.

Arc Ion Plating Deposition System의 Bias 종류에 따른 TiN 박막의 특성평가

  • Kim, Wang-Ryeol;Park, Min-Seok;Kim, Dae-Yeong;Kim, Hyeon-Seung;Gwon, Min-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.208-208
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    • 2012
  • 최근 환경문제가 많이 제기되면서 친환경적 운송수단인 자전거 개발과 관련하여 다양한 기술개발이 이루어지고 있다. 그 중 고부가가치의 서스펜션 포크의 프레임에 고기능성 표면처리로 Arc ion plating deposition system (AIPDS)을 이용하여 부식, 내마모 특성이 뛰어난 TiN 박막을 증착시켰다. AIPDS는 기존의 arc system과 달리 다원계 소재 코팅 공정조건 확립을 위하여 chamber wall에 2개의 rectangular type sputter source를 장착하고 소재의 pre-treatment 용 linear type ion source를 설치하였다. 장비의 Chamber 중앙에는 pipe형 arc cathode를 설치하였으며, 그 주위를 anode 역할을 하는 copper 코일로 감아 이는 발생한 arc를 target인 cathode 축을 중심으로 방향성을 가지고 회전하여 진행 할 수 있도록 유도 하였다. 이 시스템에서 증착된 TiN 박막은 bias 전압 변화에 따른 박막의 구조 및 물성을 평가하였다. XRD 장비를 통하여 TiN 박막의 상분석을 진행하였고, 마모테스터, 원자현미경, 마이크로 비커스 경도기 등을 이용하여 기계적 특성을 평가하였다.

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Effect of Doping Si in DLC Thin Films Growth on Their Mechanical Properties

  • Kim, Dae-Yeong;Park, Min-Seok;Jin, In-Tae
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.369.2-369.2
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    • 2014
  • Diamond-like Carbon(DLC) films doping Si were deposited by linear ion source(LIS)-physical vapor deposition method on Si wafer. We have studied the effects of Si content on friction and wear properties of DLC films and the characteristics of the films were investigated using Nano-indentation, Micro raman spectroscopy, Field Emission-Scanning Electron Microscope (FM-SEM) and X-ray Photoelectron Spectroscopy (XPS). The films has been various low-friction and low-stress by varying the flow rates of silane gas. Under the about 2% of Si doping is very suitable for improving the adhesion of films and reducing internal stress while maintaining the surfaces hardness of DLC films. Linear ion source (LIS)를 사용하여 Si wafer위에 Si 이온이 첨가된 DLC 박막을 증착하였다. 참가된Si 이온의 양에 따라 DLC 박막에 미치는 영향을 분석하기 위하여 마찰 계수 및 경도를 비교하였고, Micro raman spectroscopy, Field Emission-Scanning Electron Microscope (FM-SEM) and X-ray Photoelectron Spectroscopy (XPS)를 통하여 표면 상태를 분석하였다. 천체 주입된 가스량의 약 2%까지 Si 이온 주입이 늘어날수록 DLC 박막의 마찰계수는 낮아졌고, 경도는 Si 이온이 주입되지 않았을 경우와 비슷한 값(약 20~23 GPa)을 가졌다. 2% 이상의 주입량에서는 마찰계수는 주입량이 늘어날수록 높아졌으며 경도는 떨어지는 경향을 보였다. 이는 Si이온이 2%이하로 첨가되었을 경우, DLC 박막의 생성시 탄소 이온들의 결합 Stress를 줄여 마찰계수가 줄어든다고 볼 수 있으며, 그 양이 2%이상이 되면 오히려 불순물로 작용하여 DLC 박막의 Stress는 급격히 증가하고 마찰계수도 높아짐을 알 수 있다.

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Source Identification of Ambient PM-10 Using the PMF Model (PMF 모델을 이용한 대기 중 PM-10 오염원의 확인)

  • 황인조;김동술
    • Journal of Korean Society for Atmospheric Environment
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    • v.19 no.6
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    • pp.701-717
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    • 2003
  • The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

Diamon-like Carbon Coatings Prepared by Linear Ion Source with 20 kHz Discharge (선형 이온빔 소스의 20 kHz 방전을 이용한 DLC 박막 증착 연구)

  • Lee, Seung-Hun;Kim, Jong-Guk;Kim, Do-Geun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.262-262
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    • 2012
  • Diamond like carbon(DLC) 박막은 고경도, 초저마찰 특성을 요구하는 마찰분야에 널리 사용되며, 대면적 저가 코팅 방법 개발 및 물성 조절 기술이 요구된다. 본 연구에서는 선형 이온 소스를 통한 DLC 박막의 대면적 코팅 방법은 연구했으며, 방전 주파수 조절에 따른 박막 물성 조절 특성을 분석하였다.

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The Effect of Aluminum Element on the Surface Properties of CrAlN Coating Film Deposited via Arc Ion Plating ( Arc Ion Plating으로 증착된 CrAlN 코팅막의 표면 특성에 미치는 Al 원소의 영향 )

  • Jae-Un Kim;Byeong-Seok Lim;Young-Shin Yun;Byung-Woo Ahn;Han-Cheol Choe
    • Journal of the Korean institute of surface engineering
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    • v.57 no.1
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    • pp.14-21
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    • 2024
  • For this study, CrAlN multilayer coatings were deposited on SKD61 substrates using a multi-arc ion plating technique. The structural characteristics of the CrAlN multilayer coatings were evaluated using X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Additionally, the adhesion of the coatings was assessed through scratch testing, and the mechanical strength was evaluated using nanoindentation and tribometric tests for frictional properties. The results show that the CrAlN multilayer coatings possess a uniform and dense structure with excellent mechanical strength. Hardness measurements indicated that the CrAlN coatings have high hardness values, and both the coating adhesion and wear resistance were found to be improved compared to CrN. The addition of aluminum is anticipated to contribute to enhanced durability and wear resistance.

Discharge Gap Effects on Ion Beam Extraction in the Closed Drift Linear Ion Source (방전 간격에 따른 Closed Drift 선형 이온원의 이온빔 인출 특성 연구)

  • Lee, Seung-Hun;Kim, Jae-Un;Kim, Jong-Guk;Kim, Chang-Su;Gang, Jae-Uk;Kim, Do-Geun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.98-99
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    • 2011
  • 300 mm급 선형 이온원의 방전 간격에 따른 방전 및 이온빔 인출 특성 변화를 연구하였다. 방전 간격이 2 mm 에서 3 mm로 증가함에 따라 동일 방전 전압에서 방전 전류가 약 20% 증가하였으며, 이는 방전 공간 내 플라즈마 발생 증가에 의한 것임을 object oriented particle in cell 전산모사를 통해 확인하였다.

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마이크로·나노 구조 형성을 통한 알루미늄 표면의 발수 특성 개발

  • Byeon, Eun-Yeon;Lee, Seung-Hun;Kim, Jong-Guk;Kim, Yang-Do;Kim, Do-Geun
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.223-224
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    • 2012
  • 금속 표면에 마이크로 나노 구조물을 형성하고 그 위에 발수 특성을 가진 물질을 증착하여, 발수성을 가지는 금속 표면을 개발하였다. Sand blast 공정으로 마이크로 구조 형성, Linear Ion Source(LIS)를 적용한 Ion beam etching으로 나노 구조를 형성하였다. 그 결과 FE-SEM을 통해 수~수십 ${\mu}m$ 크기의 구조 위에 nm 크기의 구조가 형성 된 것을 확인하였다. 발수 특성은 매끈한 표면보다 거친(rough)표면과 낮은 표면에너지로 구현된다. 마이크로 나노 구조가 형성된 Al의 표면에너지를 낮추기 위해 Hexamethyldisiloxane(HMDSO)을 코팅하였다. 접촉각 측정 결과 $105^{\circ}$로 표면 형상을 제어함으로써 발수 특성이 나타나는 것을 확인하였다.

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