• 제목/요약/키워드: VUV

검색결과 118건 처리시간 0.023초

VUV 이오나이저용 Ca-Sr-Ba계 산화물 캐소드에 낮은 일함수를 갖는 금속산화물 첨가의 영향 (Effects on Addition of Metal Oxides with Low Workfunctions on the Ca-Sr-Ba Oxide Cathodes for VUV Ionizers)

  • 박승규;이종혁;김란희;정주형;한완규;이수현;전성우;김대준;김도윤;이광섭
    • 한국재료학회지
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    • 제29권4호
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    • pp.241-251
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    • 2019
  • There are several manufacturing techniques for developing thermionic cathodes for vacuum ultraviolet(VUV) ionizers. The triple alkaline earth metal emitters(Ca-Sr-Ba) are formulated as efficient and reliable thermo-electron sources with a great many different compositions for the ionizing devices. We prepare two basic suspensions with different compositions: calcium, strontium and barium. After evaluating the electron-emitting performance for europium, gadolinium, and yttrium-based cathodes mixed with these suspensions, we selected the yttrium for its better performance. Next, another transition metal indium and a lanthanide metal neodymium salt is introduced to two base emitters. These final composite metal emitters are coated on the tungsten filament and then activated to the oxide cathodes by an intentionally programmed calcination process under an ultra-high vacuum(${\sim}10^{-6}torr$). The performance of electron emission of the cathodes is characterized by their anode currents with respect to the addition of each element, In and Nd, and their concentration of cathodes. Compared to both the base cathodes, the electron emission performance of the cathodes containing indium and neodymium decreases. The anode current of the Nd cathode is more markedly degraded than that with In.

초음파 분무법으로 제조한 $(Y,Gd)BO_3:Eu^{3+}$ 형광체의 발광특성에 관한 연구 (A Study on Photoluminance Properties of $(Y,Gd)BO_3:Eu^{3+}$ Phosphor Synthesized by Ultrasonic Spray Pyrolysis)

  • 김대수;이임렬
    • 한국재료학회지
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    • 제10권3호
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    • pp.204-211
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    • 2000
  • 초음파 분무법으로 $(Y,Gd)BO_3:Eu$의 PDP 적색 형광체를 제조하여 147nm VUV 여기에 따른 발광 특성을 분석하였다. 초음파 분무에 사용된 전구체 용액은 Y, Gd, Eu의 아세트산염과 $H_3BO_3$를 증류수에 용해하여 1.7MHz의 초음파 분무기로 고온의 반응관내로 분무하였다. 분무된 액적은 반응관내에서 통과시 불충분한 반응으로 C-C와 C-H를 함유한 비정질 상이었으나, $1100^{\circ}C$에서 추가 열처리 한 시편은 고상반응법으로 제조한 형광체와 동일한 결정구조와 성분을 보였다. 고상반응법으로 제조한 형광체의 분말 크기는 $3{\mu\textrm{m}}$으로 조대하고 불균일한 분포를 보인 반면, $500^{\circ}C$에서 분무한 후 $900^{\circ}C$에서 열처리하여 제조한 $(Y_{0.7}Gd_{0.3})_{0.95}BO_3:Eu_{0.05}\;^{3+}$ 형광체의 모양은 비교적 구형이었으며 평균 입자크기는 $0.7{\mu\textrm{m}}$로 미세하고 균일한 분포를 하고 있었다. 147nm VUV 여기시 초음파 분무로 제조한 $(Y_{0.7}Gd_{0.3})_{0.95}BO_3:Eu_{0.05}\;^{3+}$ 형광체의 적색 발광강도는 고상반응법으로 제조한 시편이나 상용품인 $(Y,Gd)BO_3:Eu$ 형광체에 비해 그 휘도가 증가되었다.

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Can Diagnostics and Simulations of Microplasmas Give Suggestions for New Generation PDPs ?

  • Tachibana, Kunihide
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.1077-1080
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    • 2002
  • Present status of diagnostics and simulations on microplasmas for understandings of the discharge and VUV emission characteristics in a unit cell of plasma display panel is overviewed and their future perspective will be argued towards potential improvement of the characteristics.

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VUV MATI OF BIOLOGICAL MOLECULES

  • Choi, Kyo-Won;Lee, Joo-Hee;Kim, Sang-Kyu
    • 한국광과학회:학술대회논문집
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    • 한국광과학회 2005년도 제12회 학술대회 논문초록
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    • pp.123-123
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    • 2005
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VUV MATI OF BIOLOGICAL MOLECULES

  • Choi, Kyo-Won;Lee, Joo-Hee;Kim, Sang-Kyu
    • 한국광과학회:학술대회논문집
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    • 한국광과학회 2005년도 제12회 학술대회 논문초록
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    • pp.101-102
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    • 2005
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Binary and ternary gas mixtures of He-Ne-Xe for improvement of vacuum ultraviolet luminous efficiency in ac-PDPs.

  • Jung, Kyu-Bong;Lee, Jun-Ho;Park, Won-Bae;Jeon, Wook;Oh, Phil-Young;Cho, Guang-Sup;Uhm, Han-Sup;Choi, Eun-Ha
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.522-524
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    • 2004
  • The improvement of luminance and luminous efficiency is the one of the most important part in AC-PDPs. To achieve high luminance and luminous efficiency, high VUV emission efficiency is needed. We measured the emission spectra of vacuum ultraviolet(VUV) rays in surface discharge AC-PDP with binary and ternary gas mixtures of Ne-Xe and He-Ne-Xe. The influence of He-Ne-Xe gas-mixture ratio on excited $Xe^{\ast}$ resonant atoms and $Xe_2$$^{\ast}$ dimers has been investigated. It is found that luminous efficiency of ternary gas mixture, He-Ne-Xe, is shown to be much higher than that of binary gas mixture of Ne-Xe.

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Nano-sized $Gd_{2}O_{3}:Eu$ phosphor particles of high brightness

  • Lee, Chang-Hee;Roh, Hyun-Sook;Kang, Yun-Chan;Park, Hee-Dong;Park, Seung-Bin
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.791-794
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    • 2003
  • To synthesize $Gd_{2}O_{3}:Eu$ phosphor powder of nano size and high luminescence efficiency under UV (ultraviolet) and VUV (vacuum ultraviolet) light, organic additives such as citric acid and ethylene glycol and $Na_{2}CO_{3}$ flux were introduced in large-scale spray pyrolysis and critical conditions for forming nano-sized particles were investigated. The $Gd_{2}O_{3}:Eu$ phosphor particles prepared from solutions with organic additives such as citric acid and ethylene glycol had micron size and spherical shape. However, the particles prepared from polymeric precursor solution with $Na_{2}CO_{3}$ flux had nano size and non-aggregation characteristics. The as-prepared spherical particles with micron size turned into nano-sized particles during post-treatment by recrystallization process. The nano-sized $Gd_{2}O_{3}:Eu$ phosphor particles showed higher brightness than the commercial $Y_2O_3:Eu$ phosphor product under both UV light of 254nm and VUV light of 147 nm.

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레이저 흡수법을 이용한 제논 플라즈마 분석 (Analysis of Xe Plasma by LAS)

  • 양종경;허인성;이종찬;최용성;박대희
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.220-222
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    • 2005
  • We can classify two cases in a way to observe an atom of gas state or a molecule using the laser. First case is way to use dispersion phenomenon like Rayleigh scattering, Thomson scattering, Mie scattering, Raman Scattering. And Second case is a way to use change phenomenon like a LAS (Laser Absorption Spectroscopy), LIF (Laser Induced Fluorescent). In this paper, we have measured the meta-stable density and the distribution by using a LAS method in Xe discharge lamp. The laser absorption spectroscopy (LAS) is useful to investigate the behavior of such species. The xenon atoms in the $1S_4$ and $1S_5$ generate excited $Xe^*$(147nm) and $Xe_{2}^*$(173nm) dimers in Xe plasma. It is found that the intensity of VUV 147nm emission is proportional to that of the IR 828nm emission, and the VUV 173nm emission is roughly proportional to that of the IR 823nm emission. The laser is used CW laser that consist of AlGaAs semiconductor and energy level is used 823.16nm wavelength. We measured signal of monochrometer from the lamp center while will change a discharge electric current by 6mA in 3mA and calculated meta-stable state density of a xenon atom through a measured value.

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