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.
Experimental physics on the TCV tokamak
Experimental physics in the Basic Physics Plasma group
Experimental physics at the BioPlasmas Lab
Open positions in experimental physics on the TCV tokamak
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Model-based real-time control and scenario optimization with RAPTOR, from operation of present tokamaks to reactor design
Contact person: Dr. Simon Van Mulders, Dr. MER Olivier Sauter
Fast simulators that enable faster-than-real-time computation of heat, particle and current transport inside plasmas play an increasingly important role for tokamak operation and control. Essentially, these models help to navigate the plasma through a stable envelope within the operating space, especially during the transient phases that initiate and terminate the discharge, which are often prone to disruptions.
RAPTOR is a state-of-the-art fast transport code that has been developed in-house at the Swiss Plasma Center and has been used for pre-discharge physics scenario optimization and real-time model-based control on TCV and various other tokamaks around the world. Model-based plasma observers enhance the real-time knowledge of the plasma state by merging information coming from measurements and physics models, accounting for their respective uncertainties. The physics base of the code is being extended, for example through inclusion of impurity ion transport and neural network surrogate models for turbulent heat fluxes.
We are looking for a motivated PhD candidate to join the RAPTOR Team! The project includes further development of the RAPTOR physics models and routine application of RAPTOR for TCV operation, from pre-shot preparation to real-time control and post-shot interpretation. Furthermore, an active engagement of the PhD student in our ongoing international collaborations is foreseen. The results of this research project have direct relevance for the achievement of high-performance, disruption-free operation of ITER and the other burning plasma experiments that are presently under construction.
Further reading: https://infoscience-exports.epfl.ch/4990/
- Fast ion physics studies on TCV
Contact person: Anton Janson van Vuuren, Mario Podestà
The PhD candidate will be responsible for routine operation of fast ion diagnostics on the TCV tokamak and interpretation of the resulting experimental data, with the aim of developing an improved understanding and characterization of the mechanisms that can lead to fast ion losses and reduced performance in tokamaks. Strong interaction with modelers, both from SPC and from collaborating institutions, is expected. The candidate will also propose and conduct dedicated experiments on TCV, as well as collaborating with the broader TCV team in other ongoing areas of research for which a good experimental characterization of fast ion confinement is beneficial.
Ions with energies well above those of the thermal plasma species – i.e., suprathermal or fast ions – are critical for the good performance of fusion devices. For example, alpha particles (fast ions from fusion reactors) will represent the main source of self-heating in a fusion reactor; their good confinement is therefore critical for achieving good efficiency, whilst their loss e.g. caused by plasma instabilities may be detrimental for the reactor’s performance and safety. Present devices such as the TCV tokamak are actively studying fast ion physics to understand the mechanisms that can possibly lead to degradation of fast ion confinement. The latter include interaction of fast ions with several types of perturbations to the plasma equilibrium, including plasma instabilities and 3D (i.e. non-axisymmetric) perturbations. Understanding those mechanisms in present devices is the basis for developing more accurate and quantitative modeling and control tools to extrapolate results to future burning plasmas and fusion reactors such as ITER and DEMO.
Along with two neutral beam injectors (NBI) to generate suprathermal ions, TCV is equipped with several diagnostics for fast ion studies: neutron detectors, neutral particle analyzer (NPA) and fast ion D-Alpha (FIDA) systems for confined fast ions; a fast ion loss detector (FILD) for measuring fast ions that escape from the main plasma. The FIDA and FILD systems are expected to be the primary focus of this project.
Previous experience with fast ion diagnostics and analysis tools is desirable. Basic understanding of tokamak equilibrium properties, their modification by both internal and externally imposed perturbations, and effects on energetic particle transport is also desirable.
Open positions in experimental physics in the Basic Plasma Physics group
- Experimental and theoretical investigation of helicon waves in TORPEX
Contact: Prof. Ivo Furno, Dr. Marcelo Baquero
Helicon waves are electromagnetic waves that can propagate in magnetized plasmas at frequencies between the ion and electron cyclotron frequencies. They are very interesting in the context of low temperature plasmas because they can lead to very high ionization efficiency in the “helicon mode” regime. In that case, heating a plasma with helicons can lead to high densities approaching values seen in scrape-off layers and divertors of tokamaks.
While studies of helicon properties have been carried out since at least the 1970s, they have mainly focused on cylindrical geometries. TORPEX, a toroidal basic plasma physics device at SPC, recently underwent an upgrade in which a birdcage antenna was installed that can excite helicon waves. This has enabled studies in a toroidal geometry in a way that was previously not possible and that we have only started to investigate.
We are currently seeking a candidate to fill an open PhD position in experimental physics to pursue experiments and numerical modeling of helicon wave physics in TORPEX. These investigations lie at the intersection of several fields in science and engineering including plasma physics, electronics, control systems and simulations, thus providing a unique opportunity to develop interdisciplinary competences.
Plasma Physics Theory
- 3D non-linear MHD modelling of tokamak plasma disruptions with the JOREK code
Contact person: Dr Mengdi Kong, Dr. MER Jonathan Graves
Tokamak plasma disruption is one of the crucial questions to be addressed for the safe operation of future large tokamaks like ITER. Accompanied by an abrupt loss of plasma confinement, disruptions could lead to substantial thermal loads, electromagnetic forces and relativistic runaway electrons (REs) that damage the plasma facing components. In view of this, shattered pellet injection (SPI) will be used in ITER’s disruption mitigation system (DMS) to mitigate the detrimental effects.
During SPI, cryogenic pellets are launched and shattered into smaller fragments before being injected into the plasma. Effects of the pellet composition, size and velocity on the material assimilation and radiation properties of SPI have been studied extensively in recent years, including experiments on tokamaks like JET, AUG and DIII-D, as well as numerical modelling using codes with different complexity. Among these, interpretative modelling of experiments helps clarify the complex physics mechanisms at play during disruptions. It also contributes to the validation of the numerical model, an essential step for obtaining reliable predictions for future reactors including ITER.
The proposed PhD thesis focuses on studying the open questions on disruptions with the JOREK code, a 3D non-linear extended MHD code for realistic tokamak geometries. The PhD candidate will start with interpretative modelling of existing JET SPI discharges, for example, those seeded with impurities like neon before the SPI. Depending on the progress, the research can be extended to other machines (including future devices) and/or other topics related to disruptions, such as the chain of events leading to disruptions and/or the dynamics of REs. The proposed thesis will thus involve both numerical modelling and experimental data analyses.
- 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 at 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.