Tamer Akan

Study of Metal and Ceramic Thermionic Vacuum arc Discharges

The thermionic vacuum arc (TVA) is a new type of plasma source, which generates a pure metal and ceramic vapour plasma containing ions with a directed energy. TVA discharges can be ignited in high vacuum conditions between a heated cathode (electron gun) and an anode (tungsten crucible) containing the material. The accelerated electron beam, incident on the anode, heats the crucible, together with its contents, to a high temperature. After establishing a steady-state density of the evaporating anode material atoms, and when the voltage applied is high enough, a bright discharge is ignited between the electrodes. We generated silver and Al2O3 TVA discharges in order to compare the metal and ceramic TVA discharges. The electrical and optical characteristics of silver and Al2O3 TVA discharges were analysed. The TVA is also a new technique for the deposition of thin films. The film condenses on the sample from the plasma state of the vapour phase of the anode material, generated by a TVA. We deposited silver and Al2O3 thin films onto an aluminium substrate layer-by-layer using their TVA discharges, and produced micro and/or nano-layer Ag-Al2O3 composite samples. The composite samples using scanning electron microscopy was also analysed.

Optical properties of the atmospheric pressure helium plasma jet generated by alternative current (a.c.) power supply

In this work, an atmospheric pressure plasmajet (APPJ) was produced to generate cold flowing post-discharge plasma of pure helium gas. The main aim of this study was to generate cold flowing APPJ of pure helium gas and to determine how their optical emission spectrum change influences varying different flow rates. Lengths of early, middle, and late post-discharge plasma (jet) regions and their fluctuations were determined, respectively. Then, ignition condition dependence of the post-discharge plasma for flow rate was specified at a constant voltage. Spectroscopic studies of an atmospheric pressure plasmajet of helium were presented via analyzing OH, N2, N2+, oxygen, and helium intensities for various flow rates.

Investigation of Properties of Boron Thin Film Deposited By Thermionic Vacuum Arc Technology

In this study, we first used boron as anode material in the TVA system. We also present boron thin film deposition using TVA technology.

Applying on Bacillus cereus of Low-Pressure and Low-Temperature Plasma Jet in a Postdischarge Chamber

A low-temperature flowing postdischarge plasma reactor is first presented. The reactor is a postdischarge chamber coupled to a plasma jet system. The low-pressure flowing postdischarge (jet) in the postdischarge chamber can be generated using direct current (dc) or alternative current (ac) power supplies. A low-pressure plasma jet of Neon using a 25-kHz 25-kV ac voltage and low-pressure plasma jet of ambient air using a 5-kV dc voltage produced in the postdischarge chamber are given. By using sample holders in the postdischarge chamber, early or late flowing postdischarge (jet) can be exposed to the sample surface. In this paper, the low-temperature and low-pressure dc air plasma jet generated using the plasma jet system coupled to a postdischarge chamber is first exposed on to Bacillus cereus, as a model bacterium. The inactivation effect on Bacillus cereus of the low-temperature and low-pressure dc air plasma jet at several exposure times was observed. With treatment of 30 min of exposure times, a value below the decimal value of the used bacterium was obtained of 15 min of exposure times.

Analysis of Sterilization Effect of Atmospheric Pressure Pulsed Plasma

We have developed a new technology, the High Voltage Atmospheric Pressure Pulsed Plasma (HVAPPP), for bacteria killing. The aim of this paper is to present a simple device to generate plasma able to kill efficiently bacteria.

Studies on Ag‐Al2O3 Nano‐layer Composite Produced by the Thermionic Vacuum Arc Method (TVA)

Thermionic Vacuum Arc (TVA) is a new type plasma source and generates pure, gas and macroparticle‐free plasma. We generated silver and alumina TVA discharges and we investigated their emission properties. The deposited Ag and Al2O3 layers were imaged using Scanning Electron Microscope (SEM) and analyzed using Energy dispersive X‐ray spectroscopy (EDX).

Emission Spectra of Two Interacting Plasmas

The aim of this present paper is to put in evidence the emission spectral lines of Ar that present M‐effect at the interaction of two different ionized gas flows.

Optical Emission Spectra of Plasma Display Panel

In this study, optical emission spectra of plasma display panel (PDP) was investigated between 200–850 nm at various pressure, pure (Ar) an mixture gas (0,5Ar+0,5 N2). This device is an application of dielectric barrier discharge.