Spatial profile of Al-ZnO thin film on polycarbonate deposited by ring-shaped magnetized rf plasma sputtering with two facing cylindrical Al2O3 - ZnO targets

Radial profiles of the ion saturation current are measured in a ring-shaped magnetized radio-frequency plasma sputtering process with two facing cylindrical ZnO targets including Al2O3 (2% wt.). The profile has a non-uniform shape with a peak whose position corresponds to the target near the electrode due to the effect of the magnetic field distribution. It becomes uniform at large distances between the substrate and a target (d st ≥ 50 mm). The radial profile of the resistivity of the Al-ZnO (AZO) films deposited on a polycarbonate plate at Ar gas pressure of 0.27 Pa is uniform at about 10-3 Ω·cm for d st ≥ 50 mm. The films deposited at various positions and room-substrate-temperature also show a good crystallinity based on an X-ray diffraction peak of about 33.95 - 34.44°. The grains exhibit a preferential orientation along the [002] axis with its size ranging from 18.15 to 28.17 nm. A higher transmittance of 95.6 % in the visible region is also obtained.

High-frequency Magnetic Fluctuations in Space Plasmas and the Role of Electron Landau Damping

While low-frequency plasma fluctuations in the interplanetary space have been successfully described in the framework of classical turbulence, high-frequency fluctuations still represent a challenge for theoretical models. At these scales, kinetic plasma processes are at work, but although some of them have been identified in spacecraft measurements, their global effects on observable quantities are sometimes not fully understood. In this paper we present a new framework to the aim of describing the observed magnetic energy spectrum and directly identify in the data the presence of Landau damping as the main collisionless dissipative process in the solar wind.

Sustainability of active bulk plasma with high electronegativity incapacitive high frequency plasma

In a high-frequency capacitively coupled plasma (HF-CCP), few studies have been carried out for the transport of charged particles in the active bulk plasma with high electronegativity. The electric field E(t), specifically, time-varying reduced field E(t)/Ng provides key knowledge about the characteristics of collisional bulk plasma. Numerical modeling is the only method for estimating E(t)/Ng, while a limited number of collision cross sections and related transport parameters are available. Under these circumstances, we discuss how to estimate the reduced field E(t)/Ng, i.e., E(t) in active bulk plasma with high electronegativity in HF-CCP through investigation of the correlation between the DC-critical reduced field (E/Ng)Crit: and the HF-effective reduced field (E(t)/Ng)eff . Our previous discussion on the correlation is validated by increasing the number of results of (E(t)/Ng)eff . The relation between the electronegativity and the ionization degree is derived from the sustainable condition in the bulk plasma.

Global plasma modeling of an magnetized high-frequency plasma source in low-pressure nitrogen and oxygen for air-breathing electric propulsion applications.

This work presents a global plasma model of a gridded air-breathing electric propulsion concept based on electron-cyclotron resonance plasma operating in the pressure range of 10-3 Pa to 1 Pa. We illustrate that the global plasma model reproduces the experimental measurements of extracted current over two orders of magnitude in pressure. Consequently, we use the model to investigate the theoretical scalability of the plasma source, finding out that the plasma source performance scales reasonably well with the average absorbed power per molecule, even though this scaling factor has its limits. The global model presented in this work is a model of a specific laboratory device and, in future, it can be adapted to very low Earth orbit conditions by adjusting the boundary conditions. The model was implemented using PlasmaSolve p3s-globalmodel software and the configuration file containing all the equations is provided to the community as supplementary material.

MATHEMATICAL MODEL OF THE INTERACTION OF LOW-ENERGY INERT GAS IONS WITH POLYPROPYLENE IN RADIO-FREQUENCY PLASMA OF LOW PRESSURE

Results of the molecular dynamic simulation of the interaction of low-energy ions (from 10 to 100 eV) with the surface of polypropylene fibrous materials in low pressure radio-frequency (RF) argon plasma is presented. A full-atomic model using the LAMMPS classical molecular dynamics code was made. As a result of numerical calculations, it was found that argon ion bombardment initiates the breaking both of an intermolecular and intramolecular bond of polypropylene with sputtered particles being the hydrocarbon radicals and single atoms. The depth of implantation of the ion is determined, the change in the kinetic energy of the argon atom and the temperature of the simulated cell is obtained.