The Swiss Plasma Center seeks PhD students throughout the year and encourages candidates to apply at any time. PhD projects are discussed with the prospective thesis supervisor at SPC during the application phase, and can be tuned to the candidate’s interest. A non-exhaustive list of possible projects can be found below.
If you need more information on any proposal, send an e-mail to the corresponding contact person.
If you want to apply, please follow the procedure indicated on this page.
Thank you.
Open positions in experimental physics on the TCV tokamak
Collective Thomson Scattering on TCV
Contact person: Dr. Laurie Porte
Thomson scattering is the elastic scattering of electromagnetic radiation by free charged particles and is the low energy limit of Compton scattering. The radiation process is described by classical, relativistic electrodynamics. Thomson scattering finds application in plasma physics by the scattering from free electrons. In most circumstances Thomson scattering of electromagnetic radiation can be used to infer electron density and temperature. In more particular scattering geometry and using longer wavelength radiation Thomson scattering from free electrons may be from electrons in the Debye sphere of the plasma ions and the electron motion is no longer independent but collective and the scattering is called collective Thomson scattering (CTS). In this case the radiation is, typically, generated by a high power gyrotron at frequency close to 126GHz on TCV. CTS produces a spectrum of radiation that is affected by the ion energy distribution and the direction of the magnetic field w.r.t. the incident radiation and can furnish information on ion temperature and density (bulk plasma) and also the non-thermal, or fast, ion distribution. A CTS diagnostic is being installed on TCV, in collaboration with colleagues from the Danish Technical University (DTU), and will be used as both a bulk ion diagnostic and a fast ion diagnostic.
The PhD student will be responsible for developing experimental scenarios for CTS on TCV as well as developing data analysis techniques for the interpretation of CTS spectra. A relatively unexplored aspect of the CTS spectrum is the information that it contains on the current profile. The CTS spectrum is very sensitive to the scattering angle w.r.t. the magnetic field. The magnetic field includes a component generated by the plasma current and, therefore, CTS can yield information on the current profile and, therefore, the location and efficiency of current generated by electron cyclotron current drive (ECCD). It is this aspect of CTS that the student will be expected to explore and exploit.
Gyrotron development projects: Advancing technological limits and physics understanding
Contact person: Dr. Falk Braunmüller
Gyrotrons are high-power vacuum electron devices that turn the energy of an electron beam gyrating in a strong magnetic field into intense millimetre-wave radiation. They are the only sources that can deliver megawatt-level microwave power continuously at frequencies above 100 GHz. That makes them essential for magnetic confinement fusion, where they heat the plasma, drive current within it, and suppress instabilities with high precision. Beyond fusion, gyrotrons are used in materials processing, plasma diagnostics and high-field spectroscopy.
Gyrotron development has seen remarkable progress. European gyrotrons for the international ITER project are developed in a collaboration including the Swiss Plasma Center (SPC) and tested at the SPC-test facility FALCON to produce 1 MW at 170 GHz in long pulses (>100s). A staged development is being organized by SPC to push their efficiency of this gyrotron to beyond 50%.
Future fusion experiments and reactors like ITER, DEMO or STEP (tokamaks) or ALPHA (stellarator) each require dozens of gyrotrons for plasma heating and control. They push for tubes that deliver around 2 MW continuously, at frequencies of up to about 240 GHz, with overall efficiencies of at least 60%. Ideally, they should also be able to switch between frequencies during operation.
Meeting these targets raises open questions across physics and engineering: interaction in high-order modes, electron beam optics, multi-stage energy recovery, heat management in the cavity, and output windows made of synthetic diamond. Combining hands-on experiment, numerical simulation and theory, a PhD in this field offers the chance to help shape a key technology for the first generation of fusion power plants.
The ECRH technology team offers a PhD-topic which would hopefully act as a catalyst for the gyrotron development towards higher frequency, microwave power and higher efficiency, as well as towards more reliable and robust gyrotrons.
Open positions in Plasma Physics Theory
Simulation of the plasma dynamics at the tokamak edge
Contact person: Prof P. Ricci
The understanding turbulence in the edge of magnetic confinement device is an outstanding open issue in magnetic fusion. The physics of this region determines the boundary conditions of the whole plasma by controlling the plasma refueling, heat losses, and impurity dynamics. Edge dynamics regulates the heat load on the tokamak vessel; this is considered among the most crucial open problems for ITER and future fusion reactors. Since a few years, a project has been initiated at the SPC with the goal of improving the understanding of edge physics. This effort has significantly advanced our grasp of plasma turbulence in the edge of a relatively simple configuration, the circular limited tokamak, and we are now exploring the physics of diverted configurations. Ph.D. theses are proposed with the goal of advancing the simulation and the understanding of edge turbulence in reactor relevant conditions, in particular to consider improved plasma models and advanced exhaust configurations.
Open positions in experimental physics in the Basic Plasma Physics group
Open positions in the BioPlasmas Lab
A virtual tour of the BioPlasmas Lab can be found here:
https://www.epfl.ch/research/domains/swiss-plasma-center/virtual-tours/
The interest in Cold Atmospheric Plasmas (CAPs) is constantly growing for a wide number of applications, from medical treatments, to sterilization of bacteria, viruses, as well as fungii (plasma-agriculture). The high-energy electron population obtained with CAP results in a complex chemistry featuring a variety of Reactive Oxygen and Nitrogen Species (RONS), which have a key role in affecting the biological sample, but keeping a low ambient temperature during the process, thanks to the low energy of ions and atmospheric gas molecules.
At the BioPlamas Lab of the SPC, this interdisciplinary topic where physics, chemistry, and biology are strongly connected is explored on several projects, with a two-fold challenge: on the one hand, CAPs are developed for industrial applications to have a short-medium term impact on the society, on the other hand, the mechanism underlying the biological effects of CAPs is investigated to increase the current understanding of CAP applications, as well as to fine tune the target process.