HEPP Seminar Winter 25/26 #11: N. Nikita / F. Wouters

Monday 19 Jan 2026, 16:00 → 17:00 Europe/Berlin

HGW-GGH / GAR-D2

Daniel Told (IPP-Garching), René Bussiahn (IPP Bereich Greifswald)

https://eu02web.zoom-x.de/j/63778308490?pwd=UmmdpAfwf3LhqmoQO9MbTjVYN3kW14.1

 

ID: 637 7830 8490

Code: 492343

 

16:00 → 16:30 N. Nikita (P): Particle acceleration and emission signatures in relativistic AGN jets

Speaker: Nikita Nikita (max planck institute for plasma physics)

hepp seminar.key

16:30 → 17:00 F. Wouters (P): The avalanche source for the 3D kinetic runaway electron model in JOREK

Disruptions, i.e. major instabilities in which plasma confinement is lost, are a significant threat to tokamak operation. A particular issue that can arise during a disruption is the acceleration of some electrons to relativistic speeds, forming a so-called runaway electron (RE) beam. Once a few REs are present, they can multiply exponentially by transferring part of their energy to bulk electrons during knock-on collisions. Because the RE avalanche is exponentially sensitive to the pre-disruption plasma current, this can lead to multi-MA RE beams in large future devices, which have the potential to cause severe, localized wall damage. Therefore, it is essential to be able to accurately model both the generation and losses of REs in realistic 3D fields to develop viable mitigation methods.

For this purpose, the 3D nonlinear MHD code JOREK includes a hybrid fluid-kinetic model that describes the REs using a full-f relativistic particle-in-cell (PiC) approach with full-orbit or drift-kinetic RE descriptions. Presented here is the implementation of a relativistic knock-on collision operator together with a resampling technique that is needed to limit the number of markers, along with a first (still in progress) application.

Speaker: Fiona Wouters (IPP-Garching)

HEPP_progress_talk.pptx