| Autor: |
Garcia-Lechuga, M., Fuentes, L. M., Grützmacher, K., Pérez, C., de la Rosa, M. I. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 2014, Vol. 116 Issue 13, p133103-1-133103-8, 8p, 1 Diagram, 9 Graphs |
| Abstrakt: |
We report a detailed characterization of the spatial resolution provided by two-photon absorption spectroscopy suited for plasma diagnosis via the 1S-2S transition of atomic hydrogen for optogalvanic detection and laser induced fluorescence (LIF). A precise knowledge of the spatial resolution is crucial for a correct interpretation of measurements, if the plasma parameters to be analysed undergo strong spatial variations. The present study is based on a novel approach which provides a reliable and realistic determination of the spatial resolution. Measured irradiance distribution of laser beam waists in the overlap volume, provided by a high resolution UV camera, are employed to resolve coupled rate equations accounting for two-photon excitation, fluorescence decay and ionization. The resulting three-dimensional yield distributions reveal in detail the spatial resolution for optogalvanic and LIF detection and related saturation due to depletion. Two-photon absorption profiles broader than the Fourier transform-limited laser bandwidth are also incorporated in the calculations. The approach allows an accurate analysis of the spatial resolution present in recent and future measurements. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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