• Title/Summary/Keyword: Korean Fims

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MANUFACTURING AND TEST RESULTS OF OFF-AXIS PARABOLIC CYLINDER MIRROR FOR FIMS (FIMS에 사용되는 비축 포물 원통형 반사경의 제작과 성능 시험 결과)

  • Ryu, K.-S.;Yuk, I. S.;Seon, K.-I.;Lee, Y.-W.;Nam, U.-W.;Shin, J.-H.;Hong, S.-J.;Lee, D.-H.;Jin, H.;Oh, S.-H;Rhee, J.-G.;Min, K.-W.;Han, W.;Park, J.-H.;Edelstein, J.;Korpela, E. J.
    • Journal of Astronomy and Space Sciences
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    • v.18 no.3
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    • pp.239-248
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    • 2001
  • Far-ultraviolet IMaging Spectrograph (FIMS) is the main payload of the first Korean scientific satellite, KAISTSAT-4, which will be launched in 2002. Among the optical parts, parabolic cylinder mirror does not have any heritage from previous astronomical missions, so the manufacturing and testing process itself is a challenging issue. We describe the method of manufacturing and measuring of the off-axis parabolic cylinder mirror and our initial experiments to establish the entire manufacturing process. Using the method, the profile error can meet the specification of $lambda$ per cm which is closely related with the astronomical performances. In case of the surface roughness, temperature controlled pitch polishing reduces $R_{q}$ under 1 nm implying that scattering in the entire spectral range of FIMS is less than 2% of the incident UV light.

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Far-ultraviolet Observations of the Comet C/2001 Q4 (NEAT)

  • Lim, Yeo-Myeong;Min, Kyoung-Wook;Seon, K.I.;Han, W.;Edelstein, J.
    • Bulletin of the Korean Space Science Society
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    • 2011.04a
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    • pp.20.1-20.1
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    • 2011
  • We present the results of far-ultraviolet (FUV) observations of comet C/2001 Q4 (NEAT) obtained with Far-ultraviolet Imaging Spectrograph (FIMS) on board the Korean microsatellite STSAT-1, which operated at an altitude of 700 km in a sun-synchronous orbit. FIMS is a dual-channel imaging spectrograph (S channel 900-1150 ${\AA}$, L channel 1350-1750 ${\AA}$, ${\lambda}/{\Box}{\lambda}$ ~ 550) with large image fields of view (S: $4^{\circ}.0{\times}4'.6$, L: $7^{\circ}.5{\times}4'.3$, angular resolution 5'-10') optimized for the observation of diffuse emission of astrophysical radiation. Comet C/2001 Q4 (NEAT) was observed with a scanning survey mode when it was located around the perihelion between 8 and 15 May 2004. Several important emission lines were detected including S I (1425, 1474 ${\AA}$), C I (1561, 1657 ${\AA}$) and several emission lines of CO $A1{\cap}-X1{\sum}+$ system in the L channel. We estimated QCO = ($2.58\;{\pm}\;0.64)\;{\times}\;1028$ s-1 from the production rate of CO 1510 ${\AA}$. We obtained L-channel image which have map size of $5^{\circ}{\times}5^{\circ}$. The image was constructed for the wavelength band of L-channel (1350-1750 ${\AA}$).We also obtained radial profile of S I, C I, CO with line fitting from central coma.

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A Study of Galactic Molecular Clouds through Multiwavelength Observations

  • Park, Sung-Joon;Min, Kyoung-Wook;Seon, Kwang-Il;Han, Won-Yong;Lee, Dae-Hee;Edelstein, Jerry;Korpela, Eric;Sankrit, Ravi
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.68.1-68.1
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    • 2010
  • We focus on two Galactic molecular clouds that are located in wholly different environments and both are observed by FIMS instrument onboard STSAT-1. The Draco cloud is known as a translucent molecular cloud at high Galactic latitude. The FUV spectra show important ionic lines of C IV, Si IV+O IV], Si II* and Al II, indicating the existence of hot and warm interstellar gases in the region. The enhanced C IV emission inside the Draco cloud region is attributable to the turbulent mixing of the interacting cold and warm/hot media, which is supported by the detection of the O III] emission line and the $H{\alpha}$ feature in this region. The Si II* emission covers the remainder of the region outside the Draco cloud, in agreement with previous observations of Galactic halos. Additionally, the H2 fluorescent map is consistent with the morphology of the atomic neutral hydrogen and dust emission of the Draco cloud. In the Aquila Rift region near Galactic plane, FIMS observed that the FUV continuum emission from the core of the Aquila Rift suffers heavy dust extinction. The entire field is divided into three sub-regions that are known as the- "halo," "diffuse," and "star-forming" regions. The "diffuse" and "star-forming" regions show various prominent H2 fluorescent emission lines, while the "halo" region indicates the general ubiquitous characteristics of H2. The CLOUD model and the FUV line ratio are included here to investigate the physical conditions of each sub-region. Finally, the development of an infrared imaging system known as the MIRIS instrument onboard STSAT-3 is briefly introduced. It can be used in WIM studies through $Pa{\alpha}$ observations.

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THERMAL ANALYSIS OF FIMS TDC AND LVPS ELECTRONIC BOARDS (원자외선 분광기 TDC 및 LVPS 전자보드의 열 해석)

  • Seon, K.I.;Yuk, I.S.;Nam, U.W.;Jin, H.;Park, J.H.;Rhee, J.G.;Ryu, K.S.;Lee, D.H.;Oh, H.S.;Kong, K.K.;Han, W.;Min, K.W.;Edelstein, J.;Korpela, E.
    • Journal of Astronomy and Space Sciences
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    • v.19 no.4
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    • pp.283-292
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    • 2002
  • Electronic boards of Far-ultraviolet IMaging Spectrograph (FIMS) should be designed to maintain their performances, and their temperatures should be remained within the allowed temperatures in operational environments. Thermal analysis at the electronic board level has been performed, and it is confirmed the electronics parts could be kept within their allowed temperature ranges.

The Effect of Hydrogen on the Tribological Properties of Hydrogenated Amorphous Carbon Films

  • Shin, Jong-Han;Lim, Dae-Soon
    • The Korean Journal of Ceramics
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    • v.3 no.2
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    • pp.96-100
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    • 1997
  • Hydrogenated amorphous carbon films were deposited on silicon substrates by using an RF PECVD. The hydrogen/methane ratio was varied from 50% to 88% to study the effect of hytdrogen in the film on the tribological properties. The friction and wear behaviors of the deposited films were investigated by ball-on-disk type wear tester. FT-IR spectra were used to characterize the structure of the films. Tribological properties of carbon films were correlated with their structure such as ratio of "polymer-like" stretching type and that of sp2 bonding. The result showed that the annealing caused a decrease in the amount of wear of contacted $Si_3N_4$ balls and a increase in the coefficient of friction. Possible explanation for annealing effect was discussed by the hydrogen desorption.esorption.

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Brief Introduction to Initial Operation of FIMS: Detection of Highly Ionized Gases and Hydrogen Fluorescence

  • Ryu, Hwang-Sun;Min, Kyoung-Wook;Rhee, Jin-Geun;Oh, Seung-Han;Shinn, Jong-Ho;Wonyong Han;Seon, Kwang-Il;Nam, Uk-Won;Park, Jang-Hyun
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.52-52
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    • 2004
  • 지난해 9월 성공적으로 발사된 과학기술위성 1호의 주탑재체인 FIMS는 초기운용을 통해 우주궤도상에서 성공적으로 동작하고 있음을 확인하였다. 과학탑재체가 올려지게 되면, 초기에는 분광 성능과 위성 자세의 보정 등이 이루어지게 된다. 현재는 초기운영을 통한 보정이 마무리되어 주요 임무인 원자외선 영역의 전천탐사를 수행하고 있다. 앞으로 1년여에 걸쳐 은하 전 영역에 걸친 분광영상을 획득하게 된다. (중략)

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FIMS의 All-Sky Survey에서 관측 가능한 별들에 대한 조사

  • Jin, Ho;Kang, Ji-Na;Sun, Kwang-Il;Park, Jang-Hyun;Yuk, In-Su;Lee, Dae-Hui;Nam, Uk-Won;Han, Won-Yong;Min, Kyung-Uk;Yoo, Kwang-Sun;Lee, Jin-Geun;Oh, Seung-Han;Edelstein, Jerry;Korpela, Eric;Nishkida, Kaori
    • Bulletin of the Korean Space Science Society
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    • 2004.04a
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    • pp.98-98
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    • 2004
  • 국내 최초의 우주망원경 FIMS(Far-ultraviolet IMaging Spectrograph: 원자외선분광기)는 과학위성 1호의 주 탑재체로서 2003년 9월 27일에 발사되었다. FIMS는 발사 후 2년 동안을 기본 임무 수행기간으로 설정하여 1년은 천구전역에 대한 전천탐사(Survey)관측을, 나머지 1년은 개별 천체에 대한 관측을 수행할 목적으로 운용되고 있다. 과학임무는 우리은하에 분포하는 고온(수만-수백만)의 천체 및 가스로부터 발생하는 원자외선 영역의 방출선 관측을 주 목적으로 하고 있으며, 시험 운용을 거쳐, 현재 전천탐사모드로 운용중이다. (중략)

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과학위성 1호 구조체 개발

  • 이상현;탁경모;차원호;이준호;장태성
    • Bulletin of the Korean Space Science Society
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    • 2003.10a
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    • pp.109-109
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    • 2003
  • 원자외선분광기(FIMS), 우주물리탑재체(SPP)를 탑재한 과학기술위성 1호는 무게 약 106kg으로 고도 690km의 원형궤도에 러시아의 COSMOS-3M에 의해 플레세츠크(Plesetsk)에서 발사 되었다. 과학기술위성 1호는 적층타입(Stack Type)으로 구조체가 설계되었으며, 하나의 모듈을 하나의 구조물로 만들어 여러 개의 구조물을 쌓아 타이바(Tie Bar)를 사용하여 체결하는 방식을 채택하고 있다. 이것은 모듈을 구조체로 사용함으로써 무게를 줄일 수 있으며, 강성이 높고, 하니스 처리가 용이한 장점이 있다. 구조체는 발사환경과 우주환경을 견디도록 설계되어야 하며, 그 과정을 지상에서 시험으로 검증을 하게 된다. 본 논문은 과학기술위성 1호의 구조물 개발과정과 제작과정을 설명하고, 제작된 구조물의 시험과정과 결과를 살펴보았다.

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