Hermann Joerg

Tuesday 8
D. High Pressure Plasmas and Applications
Chair: J.-Y. Trepanier - Each talk is 10'+2' duration
› 17:00 - 17:10 (10min)
› Cabannes
Comparative study of laser induced breakdown in argon using optical emission spectroscopy and Thomson scattering
Ali Farah Sougueh  1@  , Agata Mendys  2@  , Tomek Pieta  2@  , Krzysztof Dzierzega  2@  , Stephane Pellerin  1@  , Joerg Hermann  3@  
1 : Groupe de recherches sur l'énergétique des milieux ionisés  (GREMI)  -  Website
CNRS : UMR7344, Université d'Orléans
14 Rue d'Issoudun - BP 6744 45067 ORLEANS CEDEX 2 -  France
2 : Marian Smoluchowski Institut of Physics, Jagellonian University  -  Website
Marian Smoluchowski Institut of Physics, Jagellonian University, Krakow, Poland -  Poland
3 : Laboratoire Lasers, Plasmas et Procédés photoniques  (LP3)  -  Website
CNRS : UMR6182, Université de la Méditerranée - Aix-Marseille II
Case 917 163 Avenue de Luminy 13288 MARSEILLE CEDEX 09 -  France

We investigate the laser generated plasma in argon using Thomson scattering (TS) and optical emission spectroscopy (OES) techniques. The experiment is performed with two nanosecond Nd:YAG lasers. One generates the plasma while the second one probes the formed spark. The main objective of this work is to validate results of plasma diagnostics carried out with these two methods. Moreover, the existence of local thermodynamic equilibrium is studied by comparing the rates of the collisional to radiative processes (the McWhirter criterion), as well as relaxation times and diffusion lengths of argon neutrals and ions. Our results show satisfactory agreement between electron densities obtained with these two methods while we find very big discrepancy between electron temperature determined from the TS spectra and the excitation temperature from OES data. 


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