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.

Optimization of audio - ultrasonic plasma system parameters

“…Initially, as mentioned before, it can generate an output ion beam in the range of milli-Amperes (declared in the present data), characterizing the elements of the hot plasma electrode. 4 This latter fact is also proved empirically by another method in the present experimental work. Different gasses in earlier work are experimentally tested as helium, hydrogen, argon, and nitrogen.…”

“…An elemental analysis of the electrodes is carried out using an electron microscope, an X-Ray Florescence (XRF) and an Energy Dispersive X-ray (EDX) to identify the particles depositions on the CR-39 surface. 4 This analysis demonstrates the presence of particles agglomerations due to the out-coming ion beam from plasma.…”

“…3 A field free region is created next to the plasma area to collect the output ion beam 4 free from any disturbing effects. This region deals with a lower pressure than the plasma compartment, in that way the beam trajectory will suffer fewer particles collisions.…”

“…2 Its ability to deliver a large output ion beam at a low vacuum pressure has made it fruitful in developing a new technology. Meanwhile, the basic plasma phenomena occurring in such discharge has promoted us to stimulate intensive research activity to explore its different occurring events.…”

“…With a discharge current for argon and Nitrogen gasses of I dis ≈ 470 and 360 mA respectively. 3 The important goal of the present parameters optimization is to obtain comprehensive knowledge about the output beam over a wide range of discharge power and frequency conditions, to enhance its intensity and to reveal the appropriate conditions that control the particles energy of the output beam without any extraction system. From these data, empirical knowledge can help to configure a real state of the factors that control the occurrence of the phenomenon results.…”