Matthias Graf

Numerical model of the plasmaline microwave plasma source

Summary form only given. Microwave generated reactive plasmas are due to their technical application and complexity high interest candidates for modeling by numerical simulation. Plasma models for some cases were developed by Stewart [1], Kousaka [2], Engemann [3] and others. This work focuses on the Plasmaline, a linearly extended microwave plasma source which is well suited to generate large-scale plasmas in the low-pressure range. Its use in industrial applications e.g. surface modification make it a fit target for simulation studies with the aim of facilitating the design of large-scale plasma devices and processes. For this intent a numerical model for Argon plasma was developed, solving the coupled system of Maxwell equations, continuity equations for electrons and metastable states and the electron heat equation. The solutions are self-consistently calculated with the COMSOL Multiphysics finite element simulation software. Our model can successfully predict the transient and spatial development of the sources plasma parameters (electron temperature, electron density) and field distribution for axial symmetric geometries. The simulations are in good qualitative agreement with experimental results. A quantitative verification will be implemented with a recently acquired plasma probe and will together with simulations of 3D models be pushing our model further towards the goal of an easy usable development tool for large-scale plasma sources.

NUMERICAL SIMULATION OF ADVANCED PULTRUSION PROCESSES WITH MICROWAVE HEATING

Pultrusion is a continuous and cost-effective process for a production of composite structural components with a constant cross-sectional area. This technological process could be made more effective applying instead of conventional heaters a high frequency electromagnetic energy source characterized by the fast, instantaneous, non-contact and volumetric heating. To provide better understanding of the microwave assisted pultrusion process, to support the pultrusion tooling design and process control, new simulation methodology consisting of two sub-models has been developed. Each of them is constructed by using the general-purpose FE software that results in considerable savings in development time and costs, and also makes available various modeling features of the FE package. In the first step the electromagnetic sub-model is used to evaluate the electric field distribution by solving the Maxwell’s equations with the COMSOL Multiphysics. It is necessary to note that in this submodel the transport phenomena is neglected since an influence of the pull speed of the processing material on the electric field distribution is negligible. The objective of simulations is to find the microwave field as homogeneous as possible inside the cured composite profile in the ceramic inlet. In the second step an absorption energy field in the composite material determined with the electromagnetic sub-model is used as a heating source in the pultrusion process modeled with the thermo-chemical sub-model. This simulation procedure is developed in ANSYS Mechanical environment and based on the mixed time integration scheme and nodal control volumes method to decouple the coupled energy and species equations. To demonstrate an application of the developed methodology for the design of technological process, the microwave assisted pultrusion of the cylindrical rod made of glass fibers Unifilo 4800 tex and polyester resin POLRES 305BV has been investigated. Evgeny Barkanov, Pavel Akishin, Rudolf Emmerich and Matthias Graf

Application of a MASWP: Duo_Plasmaline next generation

Summary form only given. Microwave based surface wave plasma reactors like those relying on the Duo-Plasmaline encounters large success in dielectric coating applications. But they show principal limitation to dielectric materials applications. We attempt here to present a Duo-Plasmaline NG based on the metal antenna SWP. This design would circumvent the dielectric coating limitation. The propagation length of the plasma will be reported as a function of gas pressure, microwave power and bias potential for different atmospheres like argon, nitrogen and oxygen. The plasma homogeneity will be reflected in the coating thickness evolution of a PECVD thin film along the antenna.

New microwave plasma sources for large scale applications up to atmospheric pressure

Summary form only given, as follows. Plasma technology is used in a wide field of applications for example for PECD-deposition, activation and etching. In particular microwave enhanced plasmas are very effective for activation of surfaces. Our objective targets are to construct plasma sources for large area application and plasma sources which can be used in a wide pressure regime as possible up to atmospheric pressure. In this presentation two sources for large area and wide pressure range plasma are discussed. They are based on a coaxial coupling of the magnetron and the antenna.