• 동위원소뉴스
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• no.11 s.119
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• pp.7-10
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• 2006

• Journal of the Korean Vacuum Society
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• v.13 no.2
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• pp.59-64
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• 2004

A study on the semiconductor laser-based atomic absorption spectroscopy was performed for monitoring physical vapor deposition process. Gadolinium metal was vaporized with a high evaporation rate by electron beam heating. Real-time atomic absorption spectra were measured by using tunable semiconductor laser beam at 770-794 nm (center wavelength of 780 nm) and its second harmonic at 388-396 nm. Atomic densities of metal vapor can be calculated from the absorption spectra measured. We plot the atomic densities as a function of the electron beam power and compare with the evaporation rates measured by quartz crystal monitor. We demonstrate that the semiconductor laser-based spectroscopic system developed in this study can be applied to monitor the physical vapor deposition process for other metals such as titanium.

• Korean Journal of Optics and Photonics
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• v.8 no.5
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• pp.366-371
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• 1997

We performed the velocity selective optical pumping(VSOP) spectroscopy using the rubidium atomic vapor in the room temperature. This spectroscopic technique removes the Doppler broadening by both optical pumping effect and the selection of atoms with a particular velocity. In this experiment, we used two independent lasers; one was a locked laser whose frequency was fixed and the other was a sweep laser whose frequency was tunable. The two beams were passing through the sample in the same direction unlike the conventional VSOP spectroscopy using two counter-propagating beams. We could make the velocity selective range of atoms much wider with this method than the old one.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.4
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• pp.51-58
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• 1997

I배열형 광다이오드인 EG&G Reticon을 사용하여 측정시간이 약 10[ms]인 광측정용 초고속 분광광도계를 제작하였다. 핵심 부품인 배열형 광다이오드의 물리적 특성인 화소의 균일성, 선형성, 분광감응도를 측정하였다. 화소의 균일성과 선형성은 각각 0.5[%] 이내에서 일치하였으며, 분광감응도는 400[nm]에서 900[nm]까지 표준검출기를 사용하여 구하였다. 제작된 분광광도계는 2[nm]의 대역폭으로 측정이 가능하며 측정불확도는 2[%] 정도였다. 성능평가를 위해 미표준국의 표준기준물인 2009 didymium 필터와 수은 선광원을 측정한 결과 양호한 값을 얻었다.

• Proceedings of the Optical Society of Korea Conference
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• 2000.08a
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• pp.218-219
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• 2000

공동광자감쇠 분광학(Cavity Ringdown Spectroscopy, CRDS)은 고감도의 흡수분광법으로 미량기체의 농도나 흡수분광선의 연구에 사용되어 왔으며 화염이나 플라스마에도 응용되고 있다. 이 분광법은 시간에 따라 지수함수로 감쇠하는 공동광자감쇠신호의 감쇠상수를 측정하는 기술인데, 레이저의 밴드폭이 흡수선폭보다 넓으면 감쇠신호가 지수함수에서 벗어나 오차를 발생하게 된다. 그러므로 오차를 줄이려면 좁은선폭의 레이저를 사용하거나 공동광자감쇠신호의 주파수를 분리하여야 한다. 분광선폭보다 매우 넓은 선폭의 레이저를 사용하고 분광기를 이용하여 공동광자감쇠신호를 분리하는 방법들이 제안되었다. (중략)

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.4
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• pp.397-410
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• 2018

When considering the long-term safety assessment of spent-nuclear fuel management, americium is one of the most radio-toxic actinides. Although spectroscopic methods are widely used for the study of actinide chemistry, application of those methods to americium chemistry has been limited. Herein, we purified $^{241}Am$ to obtain a highly pure stock solution required for spectroscopic studies. Quantitative and qualitative analyses of purified $^{241}Am$ were carried out using liquid scintillation counting, and gamma and alpha radiation spectrometry. Highly sensitive absorption spectrometry coupled with a liquid waveguide capillary cell and time-resolved laser fluorescence spectroscopy were employed for the study of Am(III) hydrolysis and oxalate (Ox) complexation. $Am^{3+}$ ions under acidic conditions exhibit maximum absorbance at 503 nm, with a molar absorption coefficient of $424{\pm}8cm^{-1}{\cdot}M^{-1}$. $Am(OH)_3(s)$ colloidal particles formed under near neutral pH conditions were identified by monitoring the absorbance at around 506-507 nm. The formation of ${Am(Ox)_3}^{3-}$ was detected by red-shifts of the absorption and luminescence spectra of 4 and 5 nm, respectively. In addition, considerable enhancements of the luminescence intensities were observed. The luminescence lifetime of ${Am(Ox)_3}^{3-}$ increased from 23 to 56 ns, which indicates that approximately six water molecules are replaced by carboxylate ligands in the inner-sphere of the Am(III). These results suggest that ${Am(Ox)_3}^{3-}$ is formed through the bidentate coordination of the oxalate ligands.

• Proceedings of the Optical Society of Korea Conference
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• 2002.07a
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• pp.22-23
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• 2002

최근 레이저 쿨링 및 포획 기술은 다양한 과학적 분야에 응용되고 있다. 포획 원자는 고밀도 매질이며 100 $\mu$ K 이하의 온도를 갖기 때문에 레이저 분광학 분야에서 큰 관심을 갖게 되었다. 포획된 원자에 대한 분광학적 특성 조사는 원자의 운동학적 상태뿐만 아니라 포획 원자의 내부 상태에 대한 정보를 제공해 주기 때문에 포획 및 냉각 실험에 필수라고 할 수 있다. (중략)

• Journal of the Korean Chemical Society
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• v.37 no.4
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• pp.371-377
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• 1993

Fourier Transform UV/VIS spectrometer has been modified for emission spectroscopy with the technique of supersonic expansion, in which the unstable molecular radical $CH_3S$ has been generated in a jet by a high voltage DC discharge. The fluorescence spectra of the supersonically cooled radical have been recorded on a Fourier Transform UV/VIS spectrometer. The ratio of signal to noise of the spectra has been improved substantially. Also the rotational structure has been clearly resolved for $CH_3S$ molecular radical.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.144-149
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• 1991

코헤런트 라만분광학 실험에 사용할 다중채널 데이터 수집과 제어장치를 제작하고 프로그램을 개발하였다. CARS 신호를 규격화하기 위해 두 레이저의 세기를 측정하기 위해 최대값 검출기를 제작하였고, 제작한 로직제어기를 프로그램으로 제어하여 측정을 동기시켰다. 또한 우라늄 음극전구의 optogalvanic 신호를 측정하여 섹소레이저의 파장을 교정할 수 있었다. 프로그램은 매뉴선택방식으로 작성하여 수정과 사용이 용이하도록 하였다. 실제로 압력이 100 Torr 인 질소의 CARS 신호를 측정하여 이 장치의 유용성을 확인하였다.

• Elastomers and Composites
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• v.29 no.5
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• pp.453-466
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• 1994