Basic plasma equations and determination of optical and electrical characteristics with langmuir probe measurements for plasmas generated at low pressure

In this work, basic plasma equations, classification of plasmas and their characteristics, as well as experimental setup and various theories for plasma to be obtained under low pressure in laboratory conditions are explained in detail. Quartz discharge chamber (tube) was created to obtain gas mixture discharge at low pressures. A radiofrequency (RF) power supply at 13.56 MHz is used to provide discharge between the electrical and grounding electrodes. He or Ar gases were sent as electropositive gas with electronegative gases H_2 or O_2 in the discharge chamber to form gas mixture discharges. In the discharge chamber at low pressure, mixture discharges were obtained as non-local thermodynamic equilibrium. Through the Langmuir probe and optical emission spectroscopy (OES), the plasma parameters such as electron temperature, electron density, Debye length and electron energy distribution function of the laboratory mixture discharges, ie the optical and electrical properties of the plasma, have been defined. In addition, the OES method is also used to determine the particle types that occur in the discharge. The changes of these parameters with the amount of power applied and the gas mixture ratios were investigated and the results were analyzed in detail.