The role of He in enhancing the intensity and lifetime of H and D emissions from laser-induced atmospheric-pressure plasma

Journal Article · Fri May 15 00:00:00 EDT 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3129317· OSTI ID:21352204

Kurniawan, Koo Hendrik; Lie, Tjung Jie; Suliyanti, Maria Margaretha; Hedwig, Rinda; Pardede, Marincan ^[1]; Ramli, Muliadi; Niki, Hideaki ^[2]; Abdulmadjid, Syahrun Nur; Idris, Nasrullah; Lahna, Kurnia ^[3]; Kusumoto, Yoshihumi ^[4]; Kagawa, Kiichiro ^[5]; Tjia, May On ^[6]

---

1. Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia)
2. Department of Nuclear Power and Energy Safety Engineering, Graduate School of Engineering, Fukui University, Fukui 910-8507 (Japan)
3. Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh, Nanggroe Aceh Darussalam 23111 (Indonesia)
4. Department of Chemistry and Bio-Science, Faculty of Science, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065 (Japan)
5. Department of Physics, Faculty of Education and Regional Studies, Fukui University, 9-1 Bunkyo 3-chome, Fukui 910-8507 (Japan)
6. Physics of Magnetism and Photonics Research Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha, Bandung 40132 (Indonesia)

A series of measurements have been performed on the time dependences of the intensities of helium, hydrogen, and deuterium emission lines from the corresponding laser-induced helium plasma at atmospheric pressure for two different He flow rates. The prolonged H{sub a}lpha and H{sub b}eta emissions along with their constant intensity ratio over a relatively extended period indicate the need to provide an alternative excitation mechanism other than the well-known thermal excitation process in a hot plasma. This additional excitation mechanism is also related to the metastable excited state of a He atom as indicated by the similar characteristics of the observed time dependence of the emission intensities. The enhanced intensity and lifetime of He emission at a high He flow rate was explained in terms of the collision-induced increase in the number of He atoms excited to above the 2 {sup 1}S{sub 0} metastable state, which was also responsible for the delayed excitation of H and D atoms via an energy transfer mechanism involving a Penning-like chemi-ionization process. Finally, the benefits of He-assisted delayed excitation of H and D atoms and the aforementioned enhanced intensity and lifetime at a high He flow rate were demonstrated by the achievement of clearly resolved H{sub a}lpha and D{sub a}lpha emission lines.

• OSTI ID: 21352204
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 105; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERIC PRESSURE
DEUTERIUM
ELECTRIC DISCHARGES
ELEMENTS
EMISSION
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXCITED STATES
FLOW RATE
FLUIDS
GASES
HELIUM
HOT PLASMA
HYDROGEN
HYDROGEN ISOTOPES
IONIZATION
ISOTOPES
LASERS
LIFETIME
LIGHT NUCLEI
METASTABLE STATES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
PENNING DISCHARGES
PLASMA
PLASMA DIAGNOSTICS
PLASMA PRODUCTION
RARE GASES
STABLE ISOTOPES
TIME DEPENDENCE