title: Influence of electron injection into 27 cm audio plasma cell on the plasma diagnostics.
abstract: In this article, the plasma is created in a Pyrex tube (L = 27 cm, φ = 4 cm) as a single cell, by a capacitive audio frequency (AF) discharge (f = 10-100 kHz), at a definite pressure of ~0.2 Torr. A couple of tube linear and deviating arrangements show plasma characteristic conformity. The applied AF plasma and the injection of electrons into two gas mediums Ar and N2 revealed the increase of electron density at distinct tube regions by one order to attain 10(13)∕cm(3). The electrons temperature and density strengths are in contrast to each other. While their distributions differ along the plasma tube length, they show a decaying sinusoidal shape where their peaks position varies by the gas type. The electrons injection moderates electron temperature and expands their density. The later highest peak holds for the N2 gas, at electrons injection it changes to hold for the Ar. The sinusoidal decaying density behavior generates electric fields depending on the gas used and independent of tube geometry. The effect of the injected electrons performs a responsive impact on electrons density not attributed to the gas discharge. Analytical tools investigate the interaction of the plasma, the discharge current, and the gas used on the electrodes. It points to the emigration of atoms from each one but for greater majority they behave to a preferred direction. Meanwhile, only in the linear regime, small percentage of atoms still moves in reverse direction. Traces of gas atoms revealed on both electrodes due to sheath regions denote lack of their participation in the discharge current. In addition, atoms travel from one electrode to the other by overcoming the sheaths regions occurring transportation of particles agglomeration from one electrode to the other. The electrons injection has contributed to increase the plasma electron density peaks. These electrons populations have raised the generated electrostatic fields assisting the elemental ions emigration to a preferred electrode direction. Regardless of plasma electrodes positions and plasma shape, ions can be departed from one electrode to deposit on the other one. In consequence, as an application the AF plasma type can enhance the metal deposition from one electrode to the other.
authors.affiliation: Accelerators Department, Nuclear Research Center, AEA, Cairo 13759, Egypt.
authors.forename: N A
authors.initials: NA
authors.lastname: Haleem
authors.forename: S A
authors.initials: SA
authors.lastname: El Fiki
authors.forename: S A
authors.initials: SA
authors.lastname: Nouh
authors.forename: T M
authors.initials: TM
authors.lastname: El Disoki
authors.forename: M S
authors.initials: MS
authors.lastname: Ragheb
authors.forename: S G
authors.initials: SG
authors.lastname: Zakhary