Thomas Weiland

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The optimization of continuous parameters in electrotechnical design using electromagnetic field simulation is already standard. In this paper, we present a new sequential modelling approach for mixed-integer simulation-based optimization. We apply the method for the optimization of integer-and real-valued geometrical parameters of the coils of a(More)
Many challenging modelling problems involving multi-physics arise in microelectronics; this talk will focus on some examples in the so-called Technology CAD (TCAD) area, encompassing process and device modeling, and will mention additional issues in the closely related fields of equipment and circuit/system modeling. Fully accounting for the 3D mechanical(More)
Within the design work of FAIR, beam-stability analyses play a important role. One relevant unknown is the beam response to the kicker modules. Here we report our numerical investigations of the respective longitudinal and transverse impedances, defined by Z || (ω) = 1 q 2 d 3 xE · J * ext Z x,y (ω) = i q 2 ∆ d 3 xρ ⊥ · (E x,y ∓ vB y,x), where the(More)
— A new flexible subgridding scheme for the Finite Integration Technique is presented, which can be applied for the numerical simulation of electromagnetic phenomena in static, time and frequency domains as well as for the eigenmode computation. Numerical simulations both in the static as well as in the high frequency regime are presented to give evidence(More)
The Yee finite-difference time domain method (FDTD) is commonly used in wake field and particle-in-cell simulations. However, in accelerator modeling the high energy particles can travel in vacuum faster than their own radiation. This effect is commonly referred to as numerical Cherenkov radiation and is a consequence of numerical grid dispersion. Several(More)
This paper addresses the nonlinear elliptic curl–curl equation with uncertainties in the material law. It is frequently employed in the numerical evaluation of magnetostatic fields, where the uncertainty is ascribed to the so–called B–H curve. A truncated Karhunen – Lò eve approximation of the stochastic B – H curve is presented and analyzed with regard to(More)