ISBN 9783843906784

978-3-8439-0678-4, Reihe Ingenieurwissenschaften

Jonathan Neudorfer
Numerical Methods and Computational Strategies for Particle-In-Cell Simulations of Large Scale Engineering Applications

146 Seiten, Dissertation Rheinisch-Westfälische Technische Hochschule Aachen (2012), Softcover, A5

Zusammenfassung / Abstract

This work presents techniques for the construction of a highly scalable three-dimensional Particle-In-Cell (PIC) solver for the simulation of plasma flows. The presented parallel scheme operates on unstructured meshes and is applied to the simulation of a 170 GHz gyrotron, a 2 MW microwave generator. A special challenge is presented by the numerical solution of the high frequency mode propagation inside this device. It is shown that this large-scale problem can be solved using high-order methods. The simulation of the high-frequency mode generation in the resonant cavity of the device presents a challenge for the parallelization of the scheme as well. Here, an extreme imbalance of the computational load is caused by an electron beam that occupies only a small fraction of the computational domain but requires a large part of the computational power. Yet the resulting load imbalance is effectively handled by the presented parallel scheme, allowing efficient computations on more than ten thousand CPU cores in the PIC simulation of the resonant cavity.

The three-dimensional, transient simulation of the 170 GHz gyrotron allows insights into the transient physical phenomena that have been unknown so far, thus providing a tool for the better comprehension of the device. Furthermore, it offers the possibility to solve the generation and propagation of the modes in a single simulation, allowing the identification of interactions that could not be simulated otherwise.