In both tokamaks and stellarators, stochastic magnetic fields can arise and influence the interplay between three-dimensional (3D) magnetic topology and plasma confinement. Stellarator devices represent an inherent three-dimensional challenge. They make use of the island divertor concept, and stochasticity and magnetic topology therefore play a fundamental role in their operation. With the extended operational regimes pioneered on the Large Helical Device (LHD) and with W7-X, attention has been directed towards the challenge of 3D plasma equilibria, transport and plasma–surface interactions.
In the tokamak line, non-axisymmetric magnetic perturbations, which change the magnetic topology, are applied on the majority of large-scale tokamaks nowadays to control plasma edge stability and transport. Recent research has highlighted the significance of the role that stochasticity and 3D magnetic topology also play in this fundamentally 2D concept. Their influence can be seen in transport and energy confinement, in the nature of disruption events and in the control of various magnetohydrodynamic (MHD) instabilities, most notably edge-localized modes (ELMs), which expel considerable amounts of energy from the plasma and pose a risk of damaging plasma–facing components in ITER and other next-generation fusion devices.
The existence of these stochastic and 3D effects brings tokamak and stellarator physics closer together, and a holistic approach to studying them provides the most promising path to making good progress. Understanding these effects is essential for the success of future fusion devices, and they represent a hot topic in current fusion research. In addition, reversed field pinches offer access to these topics with unique features such as the bifurcation into self-generated 3D equilibria and multi-mode unstable plasma conditions with a high degree of magnetic field stochasticity. Joint discussions of these aspects across the three communities will foster progress on basic as well as applied understanding in these complex branches of high-temperature plasma physics. Therefore, it will be of great interest and scientific importance to share the most up-to-date theories and techniques and to provide a platform for discussion between leading experts in the field.
The 10th International workshop on "Stochasticity in Fusion Plasmas (SFP)" is an attempt to discuss issues relating to impact of 3D magnetic fields on hot plasmas from all sides, bringing together experts from both tokamaks and stellarators and from different fields (equilibrium and confinement, turbulence, MHD instabilities, transport and plasma–wall interactions). This workshop will focus on the following topics: 1) Development of 3D MHD equilibrium and advanced magnetic configurations; 2) Magnetic fields/topology effects on MHD instability and turbulence transport; 3) Optimization of advanced divertor with 3D magnetic topology; 4) Plasma-wall interactions with 3D plasma boundaries.
This is the first time for this workshop being held outside of Europe. Discussing together and summarizing recent approaches will improve the physics understanding of various effects of 3D fields in magnetically confined plasmas. Analyzing the influence of stochasticity and magnetic topology in fusion plasmas will be beneficial for research in the field and will guide the design of future fusion devices. A further major goal of this workshop is to give young scientists the opportunity to enter an active and growing field of research by interacting with world-leading experts.
Topics of the workshop will include:
1. Development of 3D MHD equilibrium and advanced magnetic configurations
2. 3D magnetic fields/topology effects on MHD instability and turbulence transport
3. Optimization of advanced divertor with 3D magnetic topology
4. Plasma-wall interactions with 3D plasma boundaries