Repository logo

Infoscience

  • English
  • French
Log In
Logo EPFL, École polytechnique fédérale de Lausanne

Infoscience

  • English
  • French
Log In
  1. Home
  2. Academic and Research Output
  3. Journal articles
  4. Collisional effects on positive and negative triangularity through local and global temperature gradient-driven and flux-driven gyrokinetic simulations
 
research article

Collisional effects on positive and negative triangularity through local and global temperature gradient-driven and flux-driven gyrokinetic simulations

Di Giannatale, Giovanni  
•
Balestri, Alessandro  
•
Bottino, Alberto
Show more
August 31, 2025
Plasma Physics and Controlled Fusion

In this work, we explore the effects of collisions on turbulent transport, focusing on two different TCV magnetic equilibria featuring positive and negative triangularity. The investigation is conducted using gyrokinetic modeling. Both gradient-driven and flux-driven approaches are employed using the global code ORB5, and a comparison with GENE flux-tube modeling is also carried out. Linear and nonlinear simulations show that negative triangularity retains its beneficial effect on turbulent transport in both collisionless and collisional regimes. However, flux tube and global nonlinear simulations show contrasting trends on the impact of collisions on ion transport. Flux-driven simulations confirm that edge stiffness is significantly reduced in negative compared to positive triangularity, and a spontaneous pedestal-like logarithmic gradient develops for negative triangularity in the collisionless setup. However, without proper realistic profiles and physical boundary conditions, it is not possible to fully replicate the experimental differences observed in the temperature profiles between positive and negative triangularity. A collisionality scan reveals that the ion and electron transport coefficients do not change monotonically with collisionality, stressing how deep the interplay is between turbulent features and collisions. The general picture of collisions stabilizing TEM and damping zonal flows is confirmed, but it is shown that the effects on transport cannot be predicted without a numerical assessment.

  • Files
  • Details
  • Metrics
Loading...
Thumbnail Image
Name

Di_Giannatale_2025_Plasma_Phys._Control._Fusion_67_085003.pdf

Type

Main Document

Version

Published version

Access type

openaccess

License Condition

CC BY

Size

5.12 MB

Format

Adobe PDF

Checksum (MD5)

18c9d292b3acb615acf149424750aa77

Logo EPFL, École polytechnique fédérale de Lausanne
  • Contact
  • infoscience@epfl.ch

  • Follow us on Facebook
  • Follow us on Instagram
  • Follow us on LinkedIn
  • Follow us on X
  • Follow us on Youtube
AccessibilityLegal noticePrivacy policyCookie settingsEnd User AgreementGet helpFeedback

Infoscience is a service managed and provided by the Library and IT Services of EPFL. © EPFL, tous droits réservés