Design, characterization and applications of direct-current plasma source

In this paper, the construction and operation of a locally designed cold plasma reactor are described. The anode diameter effect was studied at three inner diameters, 5, 10 and 15 mm. This effect on the discharge and plasma characteristics was studied using oxygen and argon gases. It was found that the optimum diameter is 10 mm. Moreover, the plasma density and temperature were investigated using a cylindrical Langmuir probe at the optimum diameter. It was found that the electron temperature reaches 1.6 eV and the electron density reaches 2.3 × 10⁸ cm⁻³ in the case of oxygen gas. Moreover, X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy analyses were carried out to characterize the manganese- and cobalt-doped ferrite (Mn_0.5Co_0.5Fe₂O₄) nanoparticle sample before and after oxygen plasma irradiation. The obtained results showed that the cold plasma reactor was constructed with high efficiency to meet the required applications such as surface modification, plasma deposition and etching.