Bachelor- and master theses

for students of process engineering, physics and electrical engineering

The scope of the topics can be adjusted. Feel free to contact us.

Design of a 20 kW calorimetric dummy load for a 28 GHz heating system

  • 28 GHz gyrotron installation for TJ-K needs high power dummy load for testing and conditioning
  • Adapt existing design of cylindrical box with water-filled teflon hoses to this frequency
  • Build and test design

New Solvers for the fullwave reflectometry code IPF-FD3D

  • For the 2D version
  • Hexagonal grid: finite difference time domain (FDTD) scheme exists for vacuum, need to add plasma effects, UPML absorbing boudary conditions
  • 4th order methods: central differences in time and space AND coupling to plasma, simultaneous 4th order (simultaneous may not be possible)

Numerical investigation of poloidal correlation reflectometry

  • Microwave beam sent to plasma with several receiving antennas
  • Each receiving antenna defines different beam geometry, probing a different poloidal position
  • Correlation of signals from different positions yields poloidal rotation direction or the pitch angle of magnetic field lines
  • Turbulence from codes can be used as input for realistic scenarios

Investigations for quasi-optical mitre bends

  • Mitre-bends are the typical waveguide components for highly oversized waveguides because they are more compact than continuous bends
  • For moderately oversized waveguides, diffraction effects can partly be compensated with quasi-optical designs
  • Quasi-optical mitre-bends can accurately be calculated with PROFUSION.
  • The work consists of parameter studies for different ratios of wavelength and waveguide diameter and the investigation of the broadband performance.

Investigations of the imaging characteristics of waveguides with a non-trivial cross-section

  • Rectangular waveguides have imaging properties, which allow the design of remote steering antennas for the heating of fusion plasmas
  • The angular range is, however, limited to about +/- 12°.
  • By choosing a slightly deformed waveguide cross-section, the dispersion relation of the modes can be changed, leading to a possibly enlarged steering range.
  • An eigenmode solver for deformed cross sections is already available and can be used for parameters studies.

Design of an ultrawideband notch filter for fusion plasma diagnostics

  • ECE plasma diagnostics work in wide frequency bands that include the multi-megawatt ECR heating system frequency
  • Narrow band notch filters with +80dB rejection at the heating frequency are necessary to protect the delicate diagnostic receivers
  • Waveguide notch filters are an established technology, but such waveguides typically only support bandwidths of about 1 octave, but the diagnostic signal spans several octaves (e.g. ECE fundamental plus 2 harmonics)
  • A new optical filter design using only highpass elements combined with an interferometer setup promises ultrawide passbands
  • The work in this topic includes simple and fullwave modelling of the device and an assessment of the performance in the presence of alignment errors
  • Time permitting, a prototype can be build and measured
This image shows Carsten Lechte

Carsten Lechte

Dr. rer. nat.

Leader, Microwave Technology

This image shows Burkhard Plaum

Burkhard Plaum

Dr.-Ing.

IT and Research associate, Microwave Technology

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