Effect of copper nanoparticles on plasma glow intensity of high frequency capacitive discharge

Abstract

The paper presents the results of an experimental investigation of the effect of copper nanoparticles on plasma glow intensity of high-frequency capacitive discharge. Nanoparticles are composed of atoms, molecules and nanoclusters of copper, which are agglomerated, involving into the plasma volume. Magnetron sputtering system was used to obtain flux of copper atoms and molecules into the plasma volume. It is known that only the size and density of nanoparticles affects the optical properties of a plasma. In this case, almost any magnetron cathode material can be used as a source of nanoparticles. High-frequency plasma and magnetron discharge are ignited in the same medium with highly pure argon gas. To analyze the plasma glow intensity, the emission spectral lines with wavelengths of 737 and 750 nm were used. Thereby, it was revealed, that the density of nanoparticles in the plasma medium depends on the duration of the magnetron sputtering process and saturates with time. As the experimental results show, the plasma glow intensity with the duration of the magnetron sputtering process for 7, 14, 20 and 40 seconds, accordingly, increases in relative units ​​by 4451, 5280, 10725, 13545. That is, in this case, the plasma glow intensity with nanoparticles is three times higher than in case where nanoparticles are absent. If the sputtering process continues more than one minute, then the plasma glow intensity of does not significantly increase, this evidence the beginning of saturation of nanoparticles density in the plasma volume due to the escape of nanoparticles from the plasma volume. We believe that the experimental results find application in areas related with problems of increasing the gas-discharge glow intensity for light sources without increasing their input power.