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Public defence in Engineering Physics, M.Sc. Riccardo Iorio

Public defence from the Aalto University School of Science, Department of Applied Physics
Doctoral hat floating above a speaker's podium with a microphone

Title of the doctoral thesis: Particle scattering in magnetized plasmas: a theoretical and numerical approach

Doctoral student: Riccardo Iorio
Opponent: Docent István Pusztai, Chalmers University of Technology (Chalmers), Sweden
Custos: Prof. Mathias Groth, Aalto University School of Science, Department of Applied Physics

Exploring the Marvels of Plasmas: A Journey into Nuclear Fusion Wonders 

This research adventure delves into the captivating realm of charged particles within plasmas, unraveling valuable insights through a combination of theoretical and numerical methods. The study contributes to the ongoing exploration of nuclear fusion, a journey that began in the 1950s with the introduction of the tokamak concept. 

Beginning with a reflection on the formal derivation of the Vlasov equation, the thesis navigates through the complexities of Coulomb scattering and the Landau collision integral, utilizing non-traditional neoclassical theory for toroidal systems. This lays the groundwork for the numerical results that follow. 

In the pursuit of understanding how collisions shape plasma dynamics, the thesis provides fresh perspectives for nuclear fusion research. One notable discovery highlights the increased influence of turbulence in specific tokamak setups, particularly when investigating the connection between turbulent transport and the radial electric field. This sheds light on how variations in impurity density impact gyrokinetic simulations. Equally significant is the identification of a robust shearing phenomenon in the pedestal region, with implications for restoring transport to its neoclassical equilibrium. These findings not only deepen our comprehension of plasma behavior but also suggest practical applications, especially in optimizing plasma dynamics using methods like Lower Hybrid heating and managing turbulent transport at different radial positions. This offers potential solutions to current confinement challenges in modern fusion devices. 

The dissertation reaches its pinnacle with the formal derivation of a collisional bracket, applied to the guiding center Vlasov-Maxwell-Landau model. This theoretical breakthrough ensures the conservation of energy and momentum, with broader implications in the electromagnetic gyrokinetic case. Both from a theoretical and numerical perspective, this achievement solidifies the study's foundation, demonstrating not only conceptual clarity but also the practical applicability of the derived collisional bracket in numerical simulations. 

This study provides an engaging exploration of the world of nuclear fusion, making intricate concepts understandable and unveiling exciting avenues for future research, enhancing our understanding and opening new possibilities.

Thesis available for public display 10 days prior to the defence at: https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/

Contact details:

Email  [email protected]
Mobile  +358413145882


Doctoral theses in the School of Science: https://aaltodoc.aalto.fi/handle/123456789/52

Key words: Plasma Dynamics, Nuclear Fusion, Magnetic Confinement, Hamiltonian Methods, Coulomb Collisions

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