TY - JOUR
T1 - Investigation of helium addition for laser-induced plasma spectroscopy of pure gas phase systems
T2 - Analyte interactions and signal enhancement
AU - Henry, C. A.
AU - Diwakar, P. K.
AU - Hahn, D. W.
N1 - Funding Information:
This work was supported in part by the National Science Foundation through grant CTS-0317410. The authors express their gratitude to Prof. Nico Omenetto (University of Florida) for helpful discussions on the roles of metastable helium energy transfer.
PY - 2007/12
Y1 - 2007/12
N2 - The role of helium addition on the analyte signal enhancement in laser-induced breakdown spectroscopy for analysis of pure gaseous systems was examined using carbon and hydrogen atomic emission lines. Increased analyte response, as measured by peak-to-base and signal-to-noise ratios, was observed with increasing helium addition, with maximum enhancement approaching a factor of 7. Additional measurements revealed a significant decrease in plasma electron density with increasing helium addition. To explore the mechanisms of analyte signal enhancement, the helium emission lines were also examined and found to be effectively quenched with nitrogen addition. In consideration of the data, it is concluded that the role of metastable helium is not as important as the overall changes in plasma properties, namely electron density and laser-plasma coupling. Helium addition is concluded to affect the electron density via Penning ionization, as well as to play a role in the initial plasma breakdown processes.
AB - The role of helium addition on the analyte signal enhancement in laser-induced breakdown spectroscopy for analysis of pure gaseous systems was examined using carbon and hydrogen atomic emission lines. Increased analyte response, as measured by peak-to-base and signal-to-noise ratios, was observed with increasing helium addition, with maximum enhancement approaching a factor of 7. Additional measurements revealed a significant decrease in plasma electron density with increasing helium addition. To explore the mechanisms of analyte signal enhancement, the helium emission lines were also examined and found to be effectively quenched with nitrogen addition. In consideration of the data, it is concluded that the role of metastable helium is not as important as the overall changes in plasma properties, namely electron density and laser-plasma coupling. Helium addition is concluded to affect the electron density via Penning ionization, as well as to play a role in the initial plasma breakdown processes.
KW - Laser-induced plasma
KW - LIBS
KW - Metastable
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U2 - 10.1016/j.sab.2007.10.002
DO - 10.1016/j.sab.2007.10.002
M3 - Article
AN - SCOPUS:36749049858
SN - 0584-8547
VL - 62
SP - 1390
EP - 1398
JO - Spectrochimica Acta, Part B: Atomic Spectroscopy
JF - Spectrochimica Acta, Part B: Atomic Spectroscopy
IS - 12
ER -