• 한국항공우주학회지
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• 제39권5호
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• pp.451-457
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• 2011

레이저 조사 시 발생되는 플라즈마는 물질에 따라 특정한 파장의 빛을 방출하므로, 이 빛을 수집하여 물질의 구성 성분을 정성 정량적으로 분석할 수 있다. LIBS(Laser-Induced Breakdown Spectroscopy)는 실시간에 가까운 분석과 원거리 검출이 가능하다는 점에서 우주 자원 탐사 기술로 주목받고 있다. 본 연구에서는 달 환경, 즉 고진공 하에서의 성분 분석을 위하여 double-pulse LIBS 기법을 이용하여 LIBS 신호 세기를 크게 증가시켰다. 또한 시편에 레이저가 조사되는 각도를 조절하여 임의 형상 물질의 분석을 모사하였다.

• 한국입자에어로졸학회지
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• 제12권3호
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• pp.57-63
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• 2016

The laser-induced breakdown spectroscopy (LIBS) has been used for rapid detection of elemental compositions of various materials in multi-media (solid, liquid, gas, and aerosols). In this study, the aerosol-LIBS has been developed for real-time monitoring of process-induced particles produced during the semiconductor manufacturing. The developed aerosol-LIBS mainly consists of laser, optics, spectrometer, and aerosol chamber. A new aerosol chamber was constructed for the aerosol-LIBS to be applied for various semiconductor manufacturing process, including exhaust tubes, and low pressure and high temperature chamber. The aerosol-LIBS was evaluated by using laboratory generated aerosols for detection of various elements. As a result, P, Fe, Mg, Cu, Co, Ni, Ca, Na, and K emission lines were successfully detected by the aerosol-LIBS. Further evaluation of the aerosol-LIBS is being conducted.

• 한국추진공학회지
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• 제23권2호
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• pp.53-59
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• 2019

연소실 내부의 연료 분포를 실시간으로 측정하는 목적을 가진 소형화 장비인 LIBS plug가 개발 및 제작 되었다. LIBS plug는 레이저 유도 플라즈마 분광분석법 (Laser-induced breakdown spectroscopy : LIBS)를 응용한 장비로, 기존의 LIBS 결과인 전체 스펙트럼에서 당량비와 깊게 관여하는 두 개의 파장(H: 656.3 nm, O: 777 nm)만을 선정하여 측정할 수 있도록 하였다. 렌즈와 밴드패스 필터, 포토다이오드로 구성된 본 장비로 수집한 결과에 대한 분석이 이루어졌으며, 액체(가솔린)와 기체(LPG) 연료와 공기의 혼합물에서의 당량비 측정이 이루어졌다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.285-289
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• 2017

레이저 유도 플라즈마 분광분석법 (Laser-induced breakdown spectroscopy : LIBS) 은 기존의 레이저 기반의 연소 진단 기법들의 약한 신호세기, 복잡한 장비 구성, 낮은 정확도 등의 단점을 보완하는 기법이다. 본 연구에서는 LIBS를 활용하여 스크램 제트 엔진의 연소 가스 온도를 측정하기 위한 기초 연구가 수행되었다. 스크램 제트 엔진에서 사용되는 Jet A-1 연료로 스프레이 화염을 만들고 교정된 열전대로 화염 상부에서의 가스 온도를 측정하였다. 그리고 열전대의 온도 측정위치와 동일한 지점에서의 LIBS 신호를 획득하였다. LIBS 스펙트럼을 분석하여 LIBS 신호와 열전대로 측정된 기준 온도와의 보정곡선을 얻었다. 그래서 본 연구를 통해 LIBS를 활용하여 연소 가스의 온도를 in-situ 하게 측정할 수 있음을 확인하였다.

• 분석과학
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• 제33권2호
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• pp.86-97
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• 2020

Reconstruction and separation of explosive-contaminated overlapping fingerprints constitutes an analytical challenge of high significance in forensic sciences. Laser-induced breakdown spectroscopy (LIBS) allows real-time chemical mapping by detecting the light emissions from laser-induced plasma and can offer powerful means of fingerprint classification based on the chemical components of the sample. During recent years LIBS has been studied one of the spectroscopic techniques with larger capability for forensic sciences. However, despite of the great sensitivity, LIBS suffers from a limited detection due to difficulties in reconstruction of overlapping fingerprints. Here, the authors propose a simple, yet effective, method of using chemical mapping to separate and reconstruct the explosive-contaminated, overlapping fingerprints. A Q-switched Nd:YAG laser system (1064 nm), which allows the laser beam diameter and the area of the ablated crater to be controlled, was used to analyze the chemical compositions of eight samples of explosive-contaminated fingerprints (featuring two sample explosive and four individuals) via the LIBS. Then, the chemical validations were further performed by applying the Raman spectroscopy. The results were subjected to principal component and partial least-squares multivariate analyses, and showed the classification of contaminated fingerprints at higher than 91% accuracy. Robustness and sensitivity tests indicate that the novel method used here is effective for separating and reconstructing the overlapping fingerprints with explosive trace.

• Current Optics and Photonics
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• 제1권4호
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• pp.402-411
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• 2017

Combined LIBS-Raman spectroscopy has been widely studied, due to its complementary capabilities as an elemental analyzer that can acquire signals of atoms, ions, and molecules. In this study, the classification of polymorphs was performed by laser-induced breakdown spectroscopy (LIBS) to overcome the limitation in molecular analysis; the results were verified by Raman spectroscopy. LIBS signals of the $CaCO_3$ polymorphs calcite and aragonite, and $CaSO_4{\cdot}2H_2O$ (gypsum) and $CaSO_4$ (anhydrite), were acquired using a Nd:YAG laser (532 nm, 6 ns). While the molecular study was performed using Raman spectroscopy, LIBS could also provide sufficient key data for classifying samples containing different molecular densities and structures, using the peculiar signal ratio of $5s{\rightarrow}4p$ for the orbital transition of two polymorphs that contain Ca. The basic principle was analyzed by electronic motion in plasma and electronic transition in atoms or ions. The key factors for the classification of polymorphs were the different electron quantities in the unit-cell volume of each sample, and the selection rule in electric-dipole transitions. The present work has extended the capabilities of LIBS in molecular analysis, as well as in atomic and ionic analysis.

• 분석과학
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• 제32권4호
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• pp.121-130
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• 2019

Alumina is one of the most important ceramic materials because of its useful physical and chemical properties. Recently, high-purity alumina has been used in various industrial fields. This leads to increasing demand for reliable elemental analysis of impurities in alumina samples. However, the chemical inertness of alumina makes the sample preparation for conventional elemental analysis a tremendously difficult task. Herein, we demonstrated the feasibility of laser ablation for effective sampling of alumina powder. Laser ablation performs sampling rapidly without any chemical reagents and also allows simultaneous optical emission spectroscopy and mass spectrometry analyses. For six alumina samples including certified reference materials and commercial products, laser-induced breakdown spectroscopy (LIBS) and laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) analyses were performed simultaneously based on a common laser ablation sampling. LIBS was found to be useful to quantify alkali and alkaline earth metals with limits-of-detection (LODs) around 1 ppm. LA-ICP-MS could quantify transition metals such as Ti, Cu, Zn, and Zr with LODs in the range from a few tens to hundreds ppb.

• 한국항공우주학회지
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• 제40권4호
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• pp.346-353
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• 2012

레이저 조사 시 발생되는 플라즈마를 성분 분석에 이용하는 Laser-Induced Breakdown Spectroscopy(LIBS)는 우주 자원 탐사에 적합한 실시간 성분 분석 기술이다. LIBS 플라즈마의 특성은 주위 압력의 영향을 크게 받는다. 본 연구에서는 다양한 물성치를 갖는 일곱 가지 원소(C, Ti, Ni, Cu, Sn, Al, Zn)의 지속시간(lifetime)이 760 - $10^{-5}$ torr의 압력 범위에서 분석되었다. 압력이 낮아짐에 따라 탄소와 티타늄의 lifetime은 감소하였고, 그 밖의 원소들은 1 torr의 압력에서 가장 오랜 시간동안 검출되었다. 원소별 lifetime 결과를 통하여 낮은 압력 하에서 플라즈마의 특성과 원소별 끓는점 및 전기음성도의 관계를 규명하였다.

• 분석과학
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• 제37권1호
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• pp.12-24
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• 2024

In this study, laser-induced breakdown spectroscopy (LIBS) was used to estimate the degree of rice polishing. As-threshed rice seeds were dehusked and polished for different times, and the resulting grains were analyzed using LIBS. Various atomic, ionic, and molecular emissions were identified in the LIBS spectra. Their correlation with the amount of polished-off matter was investigated. Na I and Rb I emission line intensities showed linear sensitivity in the widest range of polished-off-matter amount. Thus, univariate models based on those lines were developed to predict the weight percent of polished-off matter and showed 3-5 % accuracy performances. Partial least squares-regression (PLS-R) was also applied to develop a multivariate model using Si I, Mg I, Ca I, Na I, K I, and Rb I emission lines. It outperformed the univariate models in prediction accuracy (2 %). Our results suggest that LIBS can be a reliable tool for authenticating the degree of rice polishing, which is closed related to nutrition, shelf life, appearance, and commercial value of rice products.

• 한국건축시공학회지
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• 제23권2호
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• pp.113-121
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• 2023

본 연구에서는 부산물(석분 슬러지, 고로슬래그, 제강슬래그, 폐콘크리트 슬러지, 바텀애시) 5종과 클링커 내 중금속 분석을 위한 레이져 유도 플라즈마 분광법(LIBS) 적용성과 재현성 검토를 실험적으로 수행하였다. 클링커를 포함한 6종의 부산물 시료에 대한 ICP-MS, XRF, LIBS 분석 결과, 정량적 분석에서 ICP와 XRF의 차이가 확인되었으나, LIBS 분석은 표준분석과 일치하지 않고 시료의 정성적인 분석만 가능하였다. LIBS를 통한 정량적 분석을 위하여 Cd, Pb, Hg에 대하여 LIBS 분석 파장(Cd - 214.44nm, Pb - 405.78nm, Hg - 253.65nm)을 설정하였고, 농도별(1~1000ppm) 용액에 함침하여 건조시킨 멤브레인 표면에 레이져를 조사한 결과, 스펙트럼 강도와 농도 사이의 상관관계를 확인할 수 있었다.