Advanced design of a low energy electron source
A multiphysics-based modeling design of a low energy electron source using a thermionic cathode is described in this paper. The proposed device produces a narrow beam employable in delicate applications where dimensions are critical. The effects of multiple physics influencing factors due to the cathode heating over the beam dynamics have been predicted through a multiphysics design approach. This paper would provide the needed knowledge for virtual prototyping of such devices. For this aim, several strategies have been adopted to obtain a simple model, which shows clearly the investigated mechanisms. According to this study, the appropriate materials and shapes can be chosen.
Computational Model of a Buncher Cavity for Millimetric Klystron
A computational model of a Buncher cavity for millimetric klystron following a Multiphysics approach is proposed in this paper. At these narrow dimensions, the device is critically exposed to multiple physics effects, due to the power dissipations and external environment, influencing the electromagnetic performances. The cavity is integrated with a carbon nanotube cold cathode in order to reduce thermal expansion and cooled by an opportune airflow that regulates the temperature distribution to compensate the resonant frequency shift. Electromagnetic fields and scattering parameters have been tested in operative conditions by concurrent computation of coupled thermodynamic, fluid dynamic, structural mechanics and electromagnetic simulations. This approach has suggested the appropriate materials and geometrical shapes.
Investigations of dielectric gratings using electrodynamic models based on volume integral equations
Eigenmodes of planar and cylindrical dielectric gratings (DGs) and electromagnetic wave scattering from multiplayer DGs are investigated. The DG characteristics are calculated using numerical-analytical solution of integral equations (IEs).