HEPP Seminar Winter 25/26 #4: Ch. Hill / L. Hollendonner / K.A. Siever

Monday 3 Nov 2025, 16:00 → 17:00 Europe/Berlin

HGW-SR2 / 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 → 16:15 Ch. Hill (I): Validation of the GENE-X gyrokinetic code on the edge and scrape-off layer of Wendelstein 7-X

Speaker: Christopher Hill

HEPP Intro Talk.pdf

16:15 → 16:45 L. Hollendonner (P): Experiment and modelling of early-heating reversed-shear discharges

This topic is all about the distribution of plasma current. In the case when most of the current is
located off-axis (contrary to the „normal“ case when the current is on-axis) the resulting profiles of
the safety factor (q-profile, bending of field-lines) is non-monotonic and there is a region of
negative shear (change of field-line bending from one flux surface to the next) which can lead to the
formation of internal transport barriers (ITBs).
The formation and sustainment of this kind of current distribution with a lot of plasma current off-
axis is not straight-forward. To this end, the approach of early-heating is pursued. This approach
slows down the current diffusion of inductive current into the core in the very early phase of a
discharge. Examples of this scenario during the last campaign and next steps to improve the
scenario in the next campaign are presented.
Another constraint on the study of transport effects of negative shear is the measurement of the
current distribution with very high precision. Thus, the second half of the talk is dedicated to
explain the working principle and some of the challenges of the relevant diagnostic.

Speaker: Lea Hollendonner (IPP-Garching)

HEPP_ProgressTalk.pdf

16:45 → 17:00 K.A. Siever (I): Radiation dynamics and stability in high radiated power fraction scenarios

Speaker: Kevin Andrea Siever (IPP Bereich Greifswald)

siever_introtalk.pdf