Influence of electron injection into 27 cm audio plasma cell on the plasma diagnostics

Abstract EN

In this article, the plasma is created in a Pyrex tube (L= 27 cm.

and =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 designs show plasma characteristic conformity for the both linear and deviating regimes.

The applied AF plasma conditions and the injection of electrons into argon and nitrogen gases medium revealed the increase of electron density magnitude by one order from 1012/cm3 to 1013/cm3 at a remarked tube regions.

The electrons temperature and density strengths are transposed 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 temperature is moderated by electrons injection, while their density is expanded.

Its higher peak is denoted for the nitrogen gas while it is reversed to the argon gas when electrons are injected.

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.

The interaction of the discharge current, the plasma type and the gas used on the electrodes are investigated by analytical tools.

Where, the elemental analysis of the electrodes after the gas discharge points to the emigration of atoms from each one but for a greater majority they behaves to a preferred direction.

Traces of gas atoms are revealed on both electrodes denoting lack of their participation in the discharge current.

In addition, atoms are proved to travel from one electrode to the other by overcoming the sheath regions and a transportation of particles agglomeration from one electrode to the other.

Meanwhile, the emigrations of other atoms in reverse direction are carried in small percentage and are performed in the linear regime only.

The electrons injected have 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 surface and deposited on the other one.

In consequence, as an application the AF plasma type could be used in metal deposition from one electrode to the other.