https://stm2.bookpi.org/PDFPANSTDR/issue/feed 2026-07-17T10:55:23+00:00 Open Journal Systems <p>The present monograph is specially focused on flowing plasmas and afterglows devices containing N₂. Several plasmas devices are presented and discussed to retain the results of plasmas that produce the highest density of active species.</p> <p>The plasmas were produced in glow discharges obtained by direct current (DC), high frequency (RF, microwaves) and arcs at low and high gas pressures, in static gas pressure after outgazing at high ultimate pumping (10^-8 Torr) and in flowing conditions at low gas pressure (10^-3 Torr) to avoid the air impurities.</p> <p>The most relevant active species in flowing plasmas are the rare gas metastable atoms and the atoms and radicals coming from dissociated molecules (N₂, H₂, O₂, CH₄).</p> <p>There is an interest of rare gas – molecules mixtures to obtain plasmas with high energy electrons in He and long residence times in Ar.</p> <p>For the first gas laser, the interest was focused on rare gas metastable atoms in He and Ar plasmas. Then for plasma chemistry and surface treatments, the N, H, O and C-atoms, NH and CN radicals were studied in flowing plasma afterglows.</p> <p>Concerning the surface treatments, the nitriding of TiO₂ thin films and the sterilization of medical instruments are focused on the plasmas setups which are producing the most high density of active species.</p> <p>To control the production of the plasma and afterglow active species, it will be emphasized the optical emission spectroscopy which is a low cost diagnostics well adapted to industrial plasma reactors.</p> <p>To obtain quantitative measurements of the active species densities, it is reported the diagnostics by optical absorption (resonant absorption for rare gas metastable atoms), by NO titration for N and O – atoms and by laser induced fluorescence (LIF, TALIF) for N, O and H-atoms.</p> <p>This last sophisticated laser method is of interest to choose the kinetics reactions allowing to interpret the results by the line ratio intensity of the optical emission spectroscopy.</p> <p>The present monograph is conduced in the order of DC glow discharges, Arc plasmas, RF and then microwave plasmas and afterglows. A comparison of RF and HF flowing plasmas and afterglows is discussed from similar setups in Ajou and Laplace Universities.</p> <p>For each studied plasma device, results are given on optical spectroscopy including LIF for the measurement of N and H active species densities.</p> https://stm2.bookpi.org/PDFPANSTDR/article/view/1501 2026-07-17T10:55:23+00:00 André RICARD [email protected]

<p>Chapter 1 reports several glow-discharge set-ups, including DC glow discharges, DC glow discharges for ion nitriding, and flowing afterglows of DC glow discharges for steel surface nitriding. Chapter 2 presents several arc-discharge systems, including the DC arc discharge, hollow-cathode arc (HCA) discharge, DC arc plasma vacuum deposition (PVD), and magnetron DC arc amplified by RF for PVD applications.</p> <p>Chapter 3 is devoted to RF plasma devices, including RF reactors for plasma-enhanced chemical vacuum deposition (PECVD), RF flowing afterglows of gas mixtures containing N₂, and flowing afterglows of high-power RF jets at atmospheric gas pressure.</p> <p>Chapter 4 discusses microwave plasma and afterglow devices, including surface-wave microwave plasmas, densities of N and H atoms and NH radicals in N₂-H₂ microwave afterglows, and microwave plasma jets at atmospheric gas pressure.</p> <p>Chapter 5 addresses applications of microwave flowing afterglows for surface treatments, including steel surface nitriding, iron nitrocarburising, polymer treatments, and medical applications.</p> <p>Chapter 6 compares RF and microwave N₂ flowing afterglow devices in relation to the densities of N atoms, N₂(A), N₂(X, v &gt; 13) metastable molecules, and N₂⁺ ions in N₂-H₂ RF and HF afterglows; in jets of N₂ RF and HF afterglows; in N and H atom and NH radical densities in N₂-H₂ RF and microwave afterglows; in N and C atom densities in N₂-CH₄ RF and microwave afterglows; and in RF and microwave flowing afterglows for TiO₂ surface activation.</p> <p>The postface summarises devices with optimal active-species densities and surface-treatment outcomes, focusing on rare-gas metastables and Ti atoms in plasmas, as well as N, H, C, and O atoms in flowing afterglows. Specific results for surface nitriding in plasma flowing afterglows are also reported.</p>

2026-07-17T00:00:00+00:00 Copyright (c) 2026 Author(s). The licensee is the publisher (BP International).