Events at Physics
Events on Monday, November 6th, 2023
- Plasma Physics (Physics/ECE/NE 922) Seminar
- “On the physical principles of power exhaust and novel divertor solutions for tokamak fusion reactors”
- Time: 12:00 pm - 1:15 pm
- Place: 1610 Engineering Hall
- Speaker: Prof. Ulrich Stroth, IPP Garching, Germany
- Abstract: Safe removal of the power generated in a fusion reactor without damaging the inner wall elements of the device is one of the most important research objectives of magnetic fusion. This presentation will introduce the main physical mechanisms by which plasma energy is dissipated before it can reach the plasma-facing components, and will explain how different divertor concepts harness them for an optimal power exhaust solution without compromising the performance of the core plasma.
A particularly attractive divertor solution was recently proposed. It bases on the occurrence of a dense, cold and strongly radiation plasma volume on closed magnetic flux surfaces near the magnetic X-point, known as X-point radiator (XPR) [1,2]. This physics of this phenomenon is well described by a reduced power balance model  and by comprehensive SOLPS-ITER transport simulations . The XPR can be real-time controlled to maintain a high-confinement plasma solution with mitigated edge-localized (ELMs) modes and a divertor fully detached from the hot plasma.
Once the XPR has been created, the magnetic configuration can be modified so that the X-point comes to lie on the wall surface, which corresponds to the compact radiative divertor (CRD) solution. In addition to the benefits of the XPR, the CRD features a number of further advantageous characteristics with regard to a reactor: it works in a much simplified divertor geometry and results in a larger and more stable plasma. Successful CRD operation was demonstrated with high-power discharges on the ASDEX Upgrade tokamak and SOLPS-ITER simulations predict its applicability to reactor size plasmas .
 Reimold F. et al., Nucl. Fusion 55, 033004 (2015)
 Bernert M. et al., J. Nucl. Mater. 12, 111 (2017)
 Stroth U. et al., Nucl. Fusion 62, 076008 (2022)
 Pan, O. et al., Nucl. Fusion 63 016001 (2023)
 Pan, O. et al., IAEA Conference, London, 2023
Prof. Ulich Stroth is a Max-Planck Director and the Head of the Division Plasma Edge and Wall, at the Max-Planck Institut für Plasmaphysik (IPP), in Garching, Germany. In addition, he is a full Professor at Technical University of Munich in the field of Experimental Plasma Physics. He earned his physics degree at the Technical University of Darmstadt and did his PhD thesis at the Institute Laue Langevin in Grenoble, France. His research interests are plasma and fluid turbulence with comparisons between experiment and simulation, microwave applications to plasmas, as well as plasma-wall interaction. Recent work addresses the development and physical understanding of sawtooth-free plasma scenarios, as well as comparison of specific aspects of plasma confinement and exhaust in stellarators and tokamaks.
- Host: Prof. Steffi Diem