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Accueil > EN > Recruitment > PhD project

Dynamics of relativistic electron bunches in synchrotron radiation facilities

par Johanna Leclercq - publié le

Title of the PhD project :
Dynamics of relativistic electron bunches in synchrotron radiation facilities


Name of the PhD Director : Serge Bielawski
Name of the co-director or collaborator : Clément Evain


Laboratory : PhLAM


Identified Research Programmes : CPER Photonics for Society, Labex CEMPI


Summary of the PhD project :
Electron accelerators are used worldwide (in synchrotron radiation facilities and Free Electron Lasers) for producing intense light at wavelengths which are difficult to obtain by other means, in particular terahertz UV and X-rays. However in these sources, interaction between accelerated electrons lead to complex phenomena, eventually leading to dynamical instabilities, and spontaneous formation of complex structures in the electron bunches. Hence understanding and controlling these instabilities has become an important subject in the development of novel new synchrotron radiation facilities and Free-Electron Lasers. Recent studies also showed that these instabilities can produce extremely intense coherent terahertz radiation. Thus part of the research also aims at using these instabilities as new terahertz sources for users, provided the dynamics may be mastered.

The PhD project will focus on several aspects this instability (known as the microbunching instability). One objective will be to use novel numerical approaches for understanding the onset of the instability, e.g., terms of bifurcations. A second objective will consist in developing strategies aiming at controlling the instability using feedback control inspired by chaos control strategies (see https://arxiv.org/abs/1810.11805 for preliminary studies). The research will be made at the interface between nonlinear dynamics and accelerator physics.

The work will be performed in close interaction with experiments performed at SOLEIL (France), KARA/ANKA (Germany), and FERMI (Italy). Numerical simulations will rely on the integration of differential equations, as Vlasov equations and particle-in-cell models. The project requires an affinity for numerical investigations.