Measurement of plasma electron density generated in an experiment of laser shock processing, utilizing the Hα-line
| Autor: | Juan Antonio Porro, José Luis Ocaña, A. Alonso-Medina, C. Colón, C. Moreno-Díaz |
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| Rok vydání: | 2016 |
| Předmět: |
Electron density
Water flow 01 natural sciences Industrial and Manufacturing Engineering Spectral line law.invention symbols.namesake Optics law 0103 physical sciences Emission spectrum 010303 astronomy & astrophysics Chemistry business.industry 010401 analytical chemistry Metals and Alloys Pulse duration Física Plasma Laser 0104 chemical sciences Computer Science Applications Stark effect Modeling and Simulation Ceramics and Composites symbols Atomic physics business |
| Zdroj: | Journal of Materials Processing Technology, ISSN 0924-0136, 2016-06, Vol. 232 Archivo Digital UPM Universidad Politécnica de Madrid |
| Popis: | In this work we have realized plasma diagnosis produced by Laser (LPP), by means of emission spectroscopy in a Laser Shock Processing (LSP). The LSP has been proposed as an alternative technology, competitive with classical surface treatments. The ionic species present in the plasma together with electron density and its temperature provide significant indicators of the degree of surface effect of the treated material. In order to analyze these indicators, we have realized spectroscopic studies of optical emission in the laser-generated plasmas in different situations. We have worked focusing on an aluminum sample (Al2024) in air and/or in LSP conditions (water flow) a Q-switched laser of Nd:YAG (λ = 1.06 μm, 10 ns of pulse duration, running at 10 Hz repetition rate). The pulse energy was set at 2,5 J per pulse. The electron density has been measured using, in every case, the Stark broadening of H Balmer α line (656.27 nm). In the case of the air, this measure has been contrasted with the value obtained with the line of 281.62 nm of Al II. Special attention has been paid to the self-absorption of the spectral lines used. The measures were realized with different delay times after the pulse of the laser (1–8 μs) and with a time window of 1 μs. In LSP the electron density obtained was between 1017 cm−3 for the shortest delays (4–6 μs), and 1016 cm−3 for the greatest delays (7,8 μs). |
| Databáze: | OpenAIRE |
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