• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2005.11a
• /
• pp.178-178
• /
• 2005

• Proceedings of the Korean Vacuum Society Conference
• /
• 2008.02a
• /
• pp.300-300
• /
• 2008

• Proceedings of the Korean Vacuum Society Conference
• /
• 2007.08a
• /
• pp.79-79
• /
• 2007

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2006.10a
• /
• pp.75-75
• /
• 2006

• Proceedings of the Korean Nuclear Society Conference
• /
• 2001.10a
• /
• pp.362.1-362
• /
• 2001

• Journal of the Korean Vacuum Society
• /
• v.18 no.3
• /
• pp.186-196
• /
• 2009

Since it is difficult to extract a high flux ion beam directly at an energy of hyperthermal range ($1{\sim}100\;eV$), especially, lower than 50 eV, the ions should be neutralized into neutral particles and extracted as a neutral beam. A plasma source required to generate and efficiently transport high flux hyperthermal neutral beams should be easily scaled up and produce a high ion density (${\ge}10^{11}\;cm^{-3}$) even at a low working pressure (${\le}$ 0.3 mTorr). It is suggested that the required plasma source can be realized by Electron Cyclotron Resonance (ECR) plasmas with diverse magnetic field configurations of permanent magnets such as a planar ECR plasma source with magnetron field configuration and cylindrical one with axial magnetic fields produced by permanent magnet arrays around chamber wall. In both case of the ECR sources, the electron confinement is based on the simple mirror field structure and efficiently enhanced by electron drifts for producing the high density plasma even at the low pressure.

• Structural Engineering and Mechanics
• /
• v.64 no.4
• /
• pp.487-494
• /
• 2017

The present paper deals with a theoretical study of delamination fracture in the Crack Lap Shear (CLS) functionally graded beam configuration. The basic purpose is to analyze the fracture with taking into account the material non-linearity. The mechanical behavior of CLS was described by using a non-linear stress-strain relation. It was assumed that the material is functionally graded along the beam height. The fracture was analyzed by applying the J-integral approach. The curvature and neutral axis coordinate of CLS beam were derived in order to solve analytically the J-integral. The non-linear solution of J-integral obtained was verified by analyzing the strain energy release rate with considering material non-linearity. The effects of material gradient, crack location along the beam height and material non-linearity on fracture behavior were evaluated. The J-integral non-linear solution derived is very suitable for parametric studies of longitudinal fracture in the CLS beam. The results obtained can be used to optimize the functionally graded beam structure with respect to the fracture performance. The analytical approach developed in the present paper contributes for the understanding of delamination fracture in functionally graded beams exhibiting material non-linearity.

• Magazine of the Korea Concrete Institute
• /
• v.10 no.6
• /
• pp.253-260
• /
• 1998

An approximate method for the calculation of creep deflections of reinforced concrete beams under sustained service loads is proposed. The position of neutral axis and strain and stress distribution of fully cracked section after creep is determined from the requirements of strain compatibility and equilibruim of a section and then the long-term flexural rigidity of fully cracked section is determined based on the new neutral axis. The long-term flexural rigidity of uncracked section at the level of the reinforcenment. The approach of calculating long-term effective flexural rigidity and defections is similar to the current American Concrete Institue procedure for calculating effecitve moment of inertia and short-term deflections. The accuracy of the analysis is verified by comparison with several experimental mesurements of beam deflectons. The result is good between the theotetical values and mesured valus.

• Proceedings of the KIEE Conference
• /
• 2003.04a
• /
• pp.355-358
• /
• 2003

본 연구에서는 차세대 초전도 핵융합장치(KSTAR)의 가열장치인 중성입자입사장치(NBI : Neutral Beam Injection) 시스템 중 휨 전자석(Bending magnet)의 중요한 파라메타인 전류에 따른 온도상승값과 B-field의 측정을 행하고 그 결과를 나타내었다. 휨 전자석(Bending magnet)은 중성입자입사장치(NBI) 시스템 중 중성화장치(Neutralizer) 후단에 설치되어, 미처 중성화되지 못한 이온들의 케도를 변경시켜 중성입자와 분리되도록 한 후 이온덤프에서 이들 이온들의 에너지가 흡수될 수 있도록 하는 역할을 한다. 사용전원은 15[V], 1200[A]의 가변전원을 사용하였고 전류값 변화에따른 온도상승값은 thermo couple 신호선을 이용하여 측정하였으며, B-field는 3차원 Gaussmeter를 이용하여 측정을 행하였다. 측정된 결과들은 설계시의 값과 비교분석을 행하여 오차를 줄여나가고자 하였고 향후 NBI 주 진공용기에 장착하여 중성입자입사장치의 개발 수행을 행하게 될 것이다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1715-1718
• /
• 2007

New ITO thin film of good performance has been developed by brand-new, plasma-damage-free sputtering process at the room temperature. The room temperature-processed ITO films with optimized conditions as neutral beam acceleration bias of -30V and In & Sn composition ratio of 99:01 gives lower resistivity as $4.22{\times}10^{-4}{\Omega}-cm$ and higher transmittance over 90% a wavelength of 550 nm. The transmission electron microscope (TEM) images of the films show a nano-crystalline structure.