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In recent years, helicon plasma sources have attracted much attention from scientific centers and industry. In this regard, the power coupling is of particular importance for the production of dense plasma in these systems. Therefore, in order to achieve maximum efficiency in these types of plasma sources, it is necessary to analyze the key parameters affecting plasma power absorption such as magnetic field (50–700 G), gas pressure (1–20 mTorr), radiofrequency power (800–2200 W), and RF frequency (6.28, 13.56, 20.34, and 27.12 MHz) applied to Nagoya antenna. Finding the optimal range of these parameters is one of the key parameters in the design and construction of helicon plasma sources. Therefore, in this article, we investigate the parameters affecting the power absorption mechanisms in these types of plasma sources using a 3-D simulation of the helicon plasma source with the finite-element method. Our findings indicate that absorption mechanisms have different effects on the absorption power due to the option of the most optimal plasma parameters’ value. The results show that changes in absorption power in terms of plasma density are nonlinear and show changes in the mode from E to H and eventually to W. Because of the domination of collisionless mechanism, the absorbed power increases in the pressures lower than 2 mTorr. In addition, at pressures above 2 mTorr, it increases due to the collisional mechanism. Plasma density increases linearly as the magnetic field intensity increases. The density peak is observed at the vacuum chamber edge in low magnetic fields (in the range of 65 G) which represents the Trivelpiece-Gould (TG) mode formation. [ABSTRACT FROM AUTHOR]

A dielectric barrier discharge device producing atmospheric argon plasma needle has been studied. The device is palpable as the jet length increases up to 10 mm by increasing the inlet gas flow up to the 7 lpm. Using spectroscopy, the electron temperature has been determined in the range of 1–10ev in different conditions. Also, a method based on the PLTE assumption is applied to the spectrums in order to calculate the electron density of the plasma needle. The electron density varies in the range of (1013–1018 cm−3). • Generation an electric discharging device with a dielectric barrier producing non-thermal plasma at atmospheric pressure. • The device is palpable as the jet length increases up to 10 mm by increasing the inlet gas flow up to the 7 lpm. • The electron temperature has been determined in the range of 1–5 ev in different conditions. • Electron density was calculated for every condition and its amount was calculated in the range of (1013–1018 cm−3). [ABSTRACT FROM AUTHOR]