• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.240-240
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• 2011

The first neutral beam injector (NBI-1) has been developed for the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. A first long pulse ion source (LPIS-1) has been installed on the NBI-1 for an auxiliary heating and current drive of KSTAR core plasmas. Performance of ion and neutral beam extractions in the LPIS-1 was investigated initially on the KSTAR NBI-1 system, prior to the neutral beam injection into the main plasmas. The ion source consists of a JAEA magnetic bucket plasma generator with multi-pole cusp fields and a set of KAERI prototype-III tetrode accelerators with circular apertures. The inner volume of plasma generator and accelerator column in the LPIS-1 is approximately 123 liters. Final design requirements for the ion source were a 120 kV/ 65 A deuterium beam and a 300 s pulse length. The extraction of ion beams was initiated by the formation of arc plasmas in the LPIS-1, called as an arc-beam extraction method. A stable ion beam extraction of LPIS-1 has been achieved up to an 100 kV/42 A for a 4 s pulse length and an 80 kV/25 A for a 14 s pulse length. Optimum beam perveance of 1.21 microperv has been found at an accelerating voltage of 80 kV. Neutralization efficiency has been measured by using a water flow calorimetry (WFC) method of calorimeter and an operation of bending magnet. The full-energy species of ion beams have been detected by using the diagnostic method of optical multichannel analyzer (OMA). An arc efficiency of the LPIS was 0.6~1.1 A/kW depending on the operating conditions of arc discharge.

• 한국자기학회지
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• 제23권4호
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• pp.135-143
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• 2013

요골 동맥의 중앙 부에 위치 한 "관"이란 곳에 영구자석 부착하여 맥의 움직임에 따라 발생하는 자기장의 변화를 홀센서로 정량화하여 맥진파형을 측정하는 집게형 맥진기를 개발하였다. 홀소자 맥진센서로 얻어진 전기적 신호로 심전도와 용적맥파계를 사용해 동시에 측정된 맥박수, 비침습적 혈압, 호흡수, 맥파전달속도와 공간맥파전달속도를 환자감시장치에 디스플레이하였다. 개발된 장치는 한방과 양방의 의료용 저장 매체와 새롭게 시도되거나 융합되어지고 있는 환자감시 장비 및 유비쿼터스 헬스케어 시스템 개발에 도움이 될 것이다.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.259-262
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• 2002

Cable-in-Conduit Conductors (CICC) have been used for fabrication of nuclear fusion magnets. Bending process is included in fabrication of superconducting magnet such as termination of conductors. Because of plastic deformation by bending process, there can be a large residual stress and change of shape in bent conductors. Void volume fraction in conductors is also changed by bending process. In this study, Commercial code was used to analyze the bending process at various bending curvature radius. The calculated residual stress of conductors bent at less than about 40cm curvature radius exceeded the allowable stress.

• E2M - 전기 전자와 첨단 소재
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• 제8권4호
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• pp.518-525
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• 1995

본 고에서는 Nb$_{3}$Sn 초전도선재의 대표적인 제조방법 및 원리 그리고 고자장마그네트 설계시 중요한 요소인 Nb$_{3}$Sn의 자장중 초전도특성 및 기계적특성 등에 대하여 고찰하고자 한다. 또한 Nb$_{3}$Sn 초전도선재의 응용분야로서 몇가지 대표적인 예를 들어 현재 세계적으로 활발하게 진행되고 있는 선진국의 고자장 초전도마그네트와 관련된 연구개발동향을 소개하고자 한다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.740-745
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• 2001

The plastic deformation behavior of formed CICC fur the superconducting Tokamac fusion device was examined and appropriate manufacturing information was provided. A relation between travel of the bending roller and spring back displacement was obtained via virtual manufacturing. The radius of CICC after forming was expressed as a function of the bend-roll travel. The maximum von Mises stress after spring back was also monitored fur the SAGBO prediction. Next, the variation of the CICC cross-sectional area was examined during the first turn and during conduit bending with the largest curvature. Finally, the coil radius was measured and compared with the data generated from the virtual manufacturing. The measured data showed similar pattern as predicted one. Using the mapping function found to match with the real data, the data from the virtual manufacturing may facilitate accurate manufacturing.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1530-1531
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• 2007

본 논문은 미러 표면에 형성된 코일과 미러 양쪽에 위치한 영구자석간의 전자기력에 의해 구동되는 마이크로미러의 설계 및 결과를 나타낸다. $4mm\;{\times}\;4mm$ 크기를 갖는 미러의 전자기 특성 및 구동을 유한요소해석 프로그램인 COMSOL Multiphysics를 이용하여 시뮬레이션 하였다. 4 kHz의 공진주파수 특성을 갖도록 설계된 마이크로미러는 코일에 $3.6\;A/mm^2$의 current density 적용 시 x-, y-axis displacement가 각각 $1.2{\mu}m$, $12{\mu}m$가 되는 것으로 나타났다.

• 한국초전도ㆍ저온공학회논문지
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• 제24권1호
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• pp.1-7
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• 2022

So far, large-scale scientific devices such as nuclear fusion tokamaks and high energy circular accelerators were constructed using high-current conductors made of metallic superconducting wires. Recently, as REBCO superconducting wires usable in high magnetic fields have been developed by several companies, researchesto apply high current cable type REBCO conductors to next-generation large superconducting magnets were also started. High critical currents of several kA or more in high magnetic fields have been successfully demonstrated on test samples of REBCO cable conductors by several research groups. In this review article, the main features and properties of the representative high current REBCO conductors such as CORC(Conductor On Round Core), TSTC(Twisted Stacked-Tape Cable) and RACC(Roebel-Assembled Coated Conductor), which are currently being developed at abroad are briefly introduced. Research activities of high-current density REBCO MHOS(Multi HTS layers on One Substrate) conductor at KERI, whose structure is different from other cable type REBCO conductors are also shortly introduced.

• 한국초전도ㆍ저온공학회논문지
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• 제13권1호
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• pp.22-26
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• 2011

As new one of superconducting power supplies, we proposed an HTS flux pump utilized a solar energy system. As an eternal electric energy can be converted by the solar system, the solar energy system is promisingly applied as an energy source in the power applications. Especially, since the solar energy system played a role in conventional utility power, total power consumption of the flux pump system are provided by solar energy. That means its operating efficiency is remarkably improved compared with developed flux pumps. A solar energy system is comprised of solar panel, photo-voltaic (PV) controller, converter and battery. The HTS flux pump consists of an electromagnet, two thermal heaters and a Bi-2223 magnet. In this paper, we describe the possibility the fusion technology between superconducting power supply and solar energy system. As a fundamental step, the fabrication, structure and experimental results are explained.

• Macromolecular Research
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• 제17권4호
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• pp.259-264
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• 2009

Chemical modification of magnetic nanoparticles(MNPs) with functional polymers has recently gained a great deal of attention because of the potential application of MNPs to in vivo and in vitro biotechnology. The potential use of MNPs as capturing agents and sensitive biosensors has been intensively investigated because MNPs exhibit good separation-capability and binding-specificity for biomolecules after suitable surface functionalization processes. In this work, we demonstrate an efficient method for the surface modification of MNPs, by combining surface-initiated polymerization and the subsequent conjugation of the biologically active molecules. The polymeric shells of non-biofouling poly(poly(ethylene glycol) methacrylate)(pPEGMA) were introduced onto the surface of MNPs by surface-initiated, atom transfer radical polymerization(SI-ATRP). With biotin as a model of biologically active compounds, the polymeric shells underwent successful post-functionalization via activation of the polymeric shells and bioconjugation of biotin. The resulting MNP hybrids showed a biospecific binding property for streptavidin and could be separated by magnet capture.

• Nuclear Engineering and Technology
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• 제56권2호
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• pp.546-551
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• 2024

As an effective methods of plasma heating, neutral beam injection (NBI) systems based on negative hydrogen ion sources will be utilized in future magnetic-confinement nuclear fusion experiments. Because of the collisions between the fast negative ions and the neutral background gas, the positive ions are inevitable created in the acceleration region in the negative NBI system. These positive ions are accelerated back into the ion source and become high energy backstreaming ions. In order to explore the characters of backstreaming ions, the track and power deposition of backstreaming H⁺ beam is estimated using the experimental and simulation methods at NNBI test facility. Results show that the flux of backstreaming positive ions is 1.93 % of that of negative ion extraction from ion source, and the magnet filed in the beam source has an effect on the backstreaming positive ions propagation.