Direct evidence of He-induced excitation process of H atoms in - PowerPoint PPT Presentation

Direct evidence of He-induced excitation process of H atoms in cooled laser plasma Koo Hendrik Kurniawan, Rinda Hedwig, Zener Sukra Lie, Kiichiro Kagawa •Research Centre of Maju Makmur Mandiri Foundation, Jakarta, Indonesia 11630 (http://www.mmmfoundation.org) •Computer Engineering Laboratory, Bina Nusantara University, Jakarta, Indonesia 11480 (http://binus.ac.id) •Research Institute of Nuclear Engineering, University of Fukui, Fukui, Japan 910-8507 ( http://www.u-fukui.ac.jp/eng)

Laser I nduce Plasma Spectroscopy Advantage Mechanism  Metal and non metal  Without pre-treatment targ arget et  In-situ analysis LASER  Micro-area analysis Time Controller OMA fibe iber 1 atm plasma Low pressure plasma He gas plasma Kagawa & Kurniawan’s Group (Cremers & Radziemski’s Group, 1981)

Practical Application of LI BS for Hydrogen Analysis I n Nuclear Power Station Problem: Hydrogen accumulation in the pipe wall degrades the pipe’s Water Zircaloy pipe strength Anticipation: Uranium Fuel Periodical Inspection Now in use Inspection Method: Gas Chromatography (sample and time consuming, hand touched radioactive and not Zircaloy pipe is an important material in situ analysis) used in a light water nuclear power New Method: station to contain uranium fuel Laser Induced Plasma Spectroscopy (LIPS)

Hydrogen Analysis Using Laser Plasma Method has not been Carried Out Before Stone sample --- High pressure (1 atm) --- Low pressure (10 torr) Why H-656.3 H is light mass “Mismatching effect” Stark broadening effect happens when plasma is produced at 1  atm Emission efficiency is very low for H atom at 1 atm due to the  “mismatching effect” Disturbance of H 2 O 

No Mismatching Effect for Other Elements Stone Si line Stone sample sample O line • Red line – High Pressure (1 atm) • Blue line – Low Pressure (10 torr)

Concept of Mismatching Effect Mismatching Ideal Shockwave Hydrogen Plasma Formation Atom Case Effect Hydrogen atoms gush out faster Time difference M H =1 between gushing early out of H atoms and M Si =28 shock-wave generation Shock-wave generation Mismatching Effect will significant at higher pressure, or at low power density, because later shockwave generation is somewhat delayed

Gas Plasma I nduced by Focusing Nd-YAG laser in the Gas To OMA Nd-YAG 120mJ Lens f 100mm (in faint ethanol vapor) N2 Gas Plasma He Gas Plasma

Time Profile of Laser I nduced Gas Plasma Emission He 587.56nm 30 Spectral width of H-656.3nm He as host gas: 25  Long Life Emission helium nitrogen  Very narrow spectral 20 limit of the system FWHM (A) width at later stage 15 Later stage is 10 N 2 as host gas: cooled plasma  Short Life Emission 5  Rather broad 0 0 5 10 15 spectral width time ( μ second)

Double Excitation Scheme for H analysis under He 1 Atm He I 667.8 nm 200 160 Ordinary LIBS Double 180 140 H I 656.2 nm 160 excitation 120 Ca I 671.7 nm intensity, counts intensity, counts 140 100 120 100 80 80 60 Ca I 671.7 nm 60 40 H I 656.2 nm 40 20 20 0 0 (b) 610 620 630 640 650 660 670 680 690 610 620 630 640 650 660 670 680 690 wavelength, nm wavelength, nm Sample: Slide glass Hydrogen Emission can be detected with high efficiency and very narrow spectral width

Experiment Setup for Proving Excitation in Cooled Plasma Stone Sample For gas Plasma: Nd-YAG (1064nm), 163mJ For ablate sample: Nd-YAG (532nm), 74mJ Delay Time between two laser: 10us In this experiment, He gas plasma was made at 5mm in front the sample. After the gas plasma formation, second laser was irradiated for ablation with 10us delay time. Atoms come out from the sample and excited in the cooled He gas plasma.

Time Profile of Emission of the Gas Plasma Due to the thermal excitation Nitrogen emission In Nitrogen gas Life time is short He-667 emission Due to the He meta-stable In helium gas excitation Life time is long

He emission proceeds in cooled plasma Two possible mechanism He ＊  He meta - He meta collision + − + → + + He * He * He ( He e ) + − + → → + He e He ** He hv  Thermal excitation from He meta + → → + * He thermal He ** He hv

The evidence to prove He emission is not due to thermal excitation Time correlation between He-501nm and He-471nm 3000 3 2.5eV 3.8eV 1He*-501 2500 2.5 2.5eV 2000 2 Intensity (a.u) Ratio 1500 1.5 not thermal 1000 1 excitation 3He*-471 500 0.5 3.8eV 0 0 0 5 10 15 20 25 30 35 40 45 Time (uS)

The Excitation Mechanism through Helium Meta-stable Penning effect X atom collides with He metastable + − + → + + He * X He ( X e ) + − + → → + X e X ** X hv X atom is ionized and Releases free electron recombination Electron recombines with X+ ion He* Spectral emission of X atom

Time Profile of H, O, Ca emission in the cooled He gas plasma Due to Helium meta-stable 35000 H I 656.2 nm excitation O I 777.1 nm 30000 Ca I 422.6 nm 25000 Low energy 20000 intensity, arb units H atoms come out faster than 15000 other atoms, which proves the 10000 “mismatching effect” 5000 0 0 500 1000 1500 2000 2500 3000 3500 4000 OMA delay, ns 60000 High energy H I 656.2 nm 50000 He I 667.8 nm Another mechanism (shock Ca I 422.6 nm (x10) 40000 wave excitation) works for O I 777.4 nm intensity, counts 30000 high energy pulse case 20000 10000 0 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 time delay

Direction of Gushing Atoms 10000 H-656nm 9000 8000 7000 6000 intensity, counts 5000 4000 Ca-422.6nm 3000 2000 1000 X Position, mm 0 -6 -4 -2 0 2 4 6 z position, mm Distribution of H atoms is more straight forwards compared to other atoms

I ntensity Calibration Curve of the Deuterium I mpurity in Zircaloy-4 Samples

Conclusion  He emission takes place through the collision of two Helium meta-stable atoms (He* ). + − + → + + → → + He * He * He ( He e ) He ** He * hv  In a cooled He plasma, Helium meta-stable atoms (He* ) excites atoms including Hydrogen + − + → + + → → + ** He X He X e He X hv * ( )  Hydrogen atoms gushed out faster than other atoms, which proved our hypothesis, namely “mismatching effect”

Published work Z.S. Lie, H. Niki, K. Kagawa, M.O. Tjia, R. Hedwig, M. Pardede, E. Jobiliong, M.M.  Suliyanti, S.N. Abdulmadjid, K.H. Kurniawan, Observation of Exclusively He-Induced H Emission in Cooled Laser Plasma , J. Appl. Phys., 109 , 10 (2011) pp. 103305 1-4 R. Hedwig, Z.S. Lie, K.H. Kurniawan, A.N. Chumakov, K. Kagawa, M.O. Tjia, Toward  Quantitative Deuterium Analysis with Laser-Induced Breakdown Spectroscopy Using Atmospheric-Pressure Helium Gas, J. Appl. Phys. 107 , 2 (2010) pp. 023301 1-5 Z.S. Lie, M. Pardede, R. Hedwig, M.M. Suliyanti, E. Steven, Maliki, Koo H. Kurniawan,  M. Ramli, S.N. Abdulmadjid, N. Idris, K. Lahna, K. Kagawa and M.O. Tjia, Intensity Distributions of Enhanced H Emission from Laser-Induced Low-Pressure He Plasma and a Suggested He-Assisted Excitation Mechanism , J. Appl. Phys., 106 , 3 (2009) pp. 043303 1-6 Koo H. Kurniawan, T.J. Lie, M.M. Suliyanti, R. Hedwig, M. Pardede, M. Ramli, H. Niki,  S.N. Abdulmadjid, N. Idris, K. Lahna, Y. Kusumoto, K. Kagawa, M.O. Tjia, The Role of He in Enhancing the Intensity and Lifetime of H and D Emissions from Laser- Induced Atmospheric-Pressure Plasma , J. Appl. Phys. 105 (2009) pp. 103303-1-6 K.H. Kurniawan, M. Pardede, R. Hedwig, Z.S. Lie, T.J. Lie, D.P. Kurniawan, M. Ramli,  K. Fukumoto, H. Niki, S.N. Abdulmadjid, N. Idris, T. Maruyama, K. Kagawa, M.O. Tjia, Quantitative Hydrogen Analysis of Zircaloy-4 Using Low-Pressure Laser Plasma Technique, Anal. Chem. 79 ,7 (2007) pp. 2703-2707 M. Pardede, R. Hedwig, M.M. Suliyanti, Z.S. Lie, T.J. Lie, D.P. Kurniawan, K.H.  Kurniawan, M. Ramli, K. Fukumoto, H. Niki, S.N. Abdulmadjid, N. Idris, T. Maruyama, K. Kagawa, M.O. Tjia, Comparative Study of Laser-Induced Plasma Emission of Hydrogen from Zircaloy-2 Samples in Atmospheric and Low Pressure Ambient Helium Gas, Appl. Phys. B. 89 , 2-3 (2007) pp. 291 - 298.