• Journal of Astronomy and Space Sciences
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• 제35권3호
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• pp.201-210
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• 2018

The characterization of detectors installed in space- and ground-based instruments is important to evaluate the system performance. We report the development of a detector performance test system for astronomical applications using the Andor iKon M CCD camera. The performance test system consists of a light source, monochromator, integrating sphere, and power meters. We adopted the Czerny-Tuner monochromator with three ruled gratings and one mirror, which covers a spectral range of 200-9,000 nm with a spectral resolution of ~1 nm in the visible region. Various detector characteristics, such as the quantum efficiency, sensitivity, and noise, can be measured in wide wavelength ranges from the visible to mid-infrared regions. We evaluated the Korea Astronomy and Space Science Institute (KASI) detector performance test system by using the performance verification of the Andor iKon-M CCD camera. The test procedure includes measurements of the conversion gain ($2.86e^-/ADU$), full well capacity ($130K\;e^-$), nonlinearity, and pixel defects. We also estimated the read noise, dark current, and quantum efficiency as a function of the temperature. The lowest measured read noise is $12e^-$. The dark current at 223 K was determined to be $7e^-/s/pix$ and its doubling temperature is $5.3^{\circ}C{\pm}0.2^{\circ}C$ at an activation energy of 0.6 eV. The maximum quantum efficiency at 223 K was estimated to be $93%{\pm}2%$. We proved that the quantum efficiency is sensitive to the operating temperature. It varies up to 5 % in the visible region, while the variation increases to 30 % in the near-infrared region. Based on the comparison of our results with the test report by the vendor, we conclude that our performance test results are consistent with those from the vendor considering the test environment. We also confirmed that the KASI detector performance test system is reliable and our measurement method and analysis are accurate.

• 조명전기설비학회논문지
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• 제25권7호
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• pp.9-14
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• 2011

A spectroscopic measuring system was developed in order to determine optical gain of gas laser discharge for any optical transitions between 190[nm] and 800[nm] without laser resonator. With an image optical system and a feedback optical system emission light of laser discharge are entered in a monochromator and received at a photomultiplier. Subsequently optical gain and line intensity are measured.

• 분석과학
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• 제15권5호
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• pp.399-409
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• 2002

글로우방전 (Glow Discharge)을 이용한 원자방출 분광계의 On-line 분광분석을 위해 개발된 본 시스템을 위한 프로그램은 주변 광학기기들을 제어하는 부분과 스펙트럼의 비선형적인 오차를 줄여 보다 정확한 결과를 얻기 위해 인공지능 기법을 도입한 스펙트럼 해석 부분으로 구성되어져 있다. McPHERSON 207 Monochromator를 GPIB 통신 프로토콜로서 제어하였으며, (주)Photon_Tek에서 제작한 A/D Amplifier를 사용하여 PMT로부터 검출 신호를 측정할 수 있었다. 인공지능 기법인 HNN(Hybrid Neural Network)을 스펙트럼 해석 부분에 도입하여 P, Cu, Fe, Cr, 등의 정성 분석과, Cd 10 ppb의 미량 검출을 통한 정량분석을 기존의 상용화된 방법보다 정확하게 수행할 수 있었다.

• 분석과학
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• 제16권3호
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• pp.226-231
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• 2003

국내와 국외에서 생산된 두 가지 종류의 AAS 기기를 이용하여 대기분진 시료를 분석하였다. 국내에서 생산된 제품의 경우, 단색화 장치의 성능면에서 선택된 파장들에 대한 광량의 세기가 우수하게 관찰되었다. 그리고 원자화장치의 경우, 재현성을 높이기 위하여 미세방울을 제외한 모든 큰 방울을 폐기 잔유물이 남지 않도록 하였다. 기기의 검출부에서는 저역 통과 filter를 사용하여, 데이터의 노이즈를 줄였다. Au 표준 용액을 이용한 검출한계 실험 분석치는 약 $0.015{\mu}g/L$ 수준의 높은 감도로서 외국사의 성능과 뚜렷한 큰 차이를 구분하기는 어려웠다. 본 연구진은 이러한 분석기법을 활용하여 서울시내 7개 지역 주요 관측점을 중심으로 2001년부터 2002년 봄까지 일년 동안 대기보전시료를 채취하였다. 이들 시료를 이용하여 분진 중에 결합된 중금속성분의 (Pb, Cu, Mn, Cd, Ni, Fe, Cr, Co, Mg, Al) 농도를 분석하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2009년도 제38회 동계학술대회 초록집
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• pp.475-475
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• 2010

We have generated Ar plasma in dense plasma focus device with coaxial electrodes for extreme ultraviolet (EUV) lithography and investigated an emitted visible light for electro-optical plasma diagnostics. We have applied an input voltage 4.5 kV to the capacitor bank of 1.53 uF and the diode chamber has been filled with Ar gas of pressure 8 mTorr. The inner surface of the cylindrical cathode has been attatched by an acetal insulator. Also, the anode made of tin metal. If we assumed that the focused plasma regions satisfy the local thermodynamic equilibrium (LTE) conditions, the electron temperature and density of the coaxial plasma focus could be obtained by Stark broadening of optical emission spectroscopy (OES). The Lorentzian profile for emission lines of Ar I of 426.629 nm and Ar II of 487.99 nm were measured with a visible monochromator. And the electron density has been estimated by FWHM (Full Width Half Maximum) of its profile. To find the exact value of FWHM, we observed the instrument line broadening of the monochromator with a Hg-Ar reference lamp. The electron temperature has been calculated using the two relative electron density ratios of the Stark profiles. In case of electron density, it has been observed by the Stark broadening method. This experiment result shows the temporal behavior of the electron temperature and density characteristics for the focused plasma. The EUV emission signal whose wavelength is about 6 ~ 16 nm has been detected by using a photo-detector (AXUV-100 Zr/C, IRD). The result compared the electron temperature and density with the temporal EUV signal. The electron density and temperature were observed to be $10^{16}\;cm^{-3}$ and 20 ~ 30 eV, respectively.

• Macromolecular Research
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• 제16권7호
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• pp.575-585
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• 2008

There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.

• Nuclear Engineering and Technology
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• 제52권9호
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• pp.2138-2150
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• 2020

We report the status of the cold neutron triple-axis spectrometer (Cold TAS) and thermal neutron triple-axis spectrometer (Thermal TAS) installed at HANARO. Cold TAS, whose specifications are standard across the world, is in the final phase of commissioning. Proper instrument operation was confirmed through a feasibility study of phonon measurements and data analyses with resolution convolution. In contrast, Thermal TAS is in the initial phase of commissioning, and improvement of the monochromator drum is now in progress from the viewpoint of radiation shielding. In addition, we report recent activities in the development of neutron basic elements, that is, film-coated Si-wafer collimators, which are promising for use in triple-axis spectroscopy, particularly in Cold TAS.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.155.1-155.1
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• 2015

Nowadays, Plasma has been used in biological, medical such as wound healing, plant grow, killing cancer. When plasma generated, UV light and ROS(Reactive oxygen species), RNS(Reactive nitrogen species) can generated and those things effect to biological material. So we made simple plasma device using needle type of electrode and generated plasma. We used three kinds of gas and measured applied voltage and current. Also we observed optical emission spectrum. Using deuterium ramp, we can observed absorption spectrum and calculated radical density by lambert-beer's law. It is around ~1016cm3. And we can see the time-resolved absorption spectrum from monochromator, PMT(photo multiply tube), IV-converter, oscilloscope.

• 한국광학회:학술대회논문집
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• 한국광학회 2009년도 동계학술발표회 논문집
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• pp.293-294
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• 2009

The spectral responsivity of solar cells has been measured under high background irradiance using an LED-based differential spectral responsivity Comparator (DSR-C). The comparator developed is fully automated and has some advantages: It does not need a chopper to modulate the light. Unlike the conventional method, it does not require a monochromator to select wavelength. It covers a wavelength range up to 1200 nm. The wavelength range of the comparator is limited by the spectral power distribution of the LEDs and the spectral responsivity of the standard detector. An active temperature control was utilized to meet the specified standard conditions of solar cell test. This work shows the effect of different levels of background irradiance on the spectral responsivity and the importance of same background irradiance for solar cell test as specified by the corresponding standard.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1990년도 추계학술발표회논문집
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• pp.17-22
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• 1990

A computer program to calculate the color temperature (To) and color rendering index (Ra) of the light source was developed. Using this program and a measuring system with a monochromator and a integrating sphere, To and Ra of incandescent lamp and fluorescent lamp was calculated. As a result, it is known that To of the I/L and the F/L with a reactor ballast is changing about 40˚K with varying source voltage of 5 V. Ra variations of these lamps have a trend but can be disregarded.