Hot fusion plasma can be effectively confined by a helical magnetic field. A magnetic field with such a topology can be created to be axially symmetric (tokamak-type devices) or has no axial symmetry (stellarator-type devices). The advantage of non-axially symmetrical devices is that their magnetic field can be created using a combination of flat and curved magnetic coils, which can be designed to minimize the losses caused by neoclassical transport. This design strategy can result in anomalous/turbulent transport processes playing an important role in the energy confinement of the hot plasma. Whatever type of device is considered, it can be seen that at the edge of the device, in the regions of plasma edge and scrape of layer, the plasma flows can typically be turbulent. Experimental experience has also shown that, among other things, so-called “interchange” instabilities appear at the edge of the plasma and can be examined by spectroscopy in the visible wavelength range. These short-lived “filaments”, elongated along magnetic field lines, can play an important role in turbulent transport.
The task of the PhD student is to systematically and comparatively investigate the edge plasma filaments observed in different fusion devices. The most important diagnostic methods used for the investigations are the alkaline atomic beam emission spectroscopy and the ultrafast video diagnostics. The student participates in experiments on various European tokamak and stellarator type devices and in the evaluation and interpretation of the results obtained during experiments on these devices. This requires good numerical skills and the communication skills to conduct scientific research in a large international research team.
Good command of professional English language, and knowledge of basic plasma physics and good programming skills are required.