ORB5 modeling of Alfven eigenmodes in NT

A. Mishchenko, G. Di Giannatale, B. Rofman, L. Villard, T. Hayward-Schneider, TSVV10 team

Introduction

  • TSVV10 has accumulated experience in global GK simulations of AEs and EM turbulence
  • Transfer this experience to NT plasma modelling (TSVV2 area of expertise)

Geometry and profiles

TCV geometry (Lx=700 for AEs, Lx=350 for turbulence). Flat bulk plasma for AEs.

Alfven Eigenmodes: PT vs NT in “TCV”

TAE instability (electrostatic potential, poloildal cross-section).
Left: positive triangularity. Right: negative triangularity.

Alfven Eigenmodes: PT vs NT in “TCV”

TAE instability (evolution of the electrostatic potential).
Left: positive triangularity. Right: negative triangularity.

Alfven Eigenmodes: PT vs NT in “TCV”

Frequency and growth rate as a function of fast-ion energy. FLR neglected for fast ions.

Alfven Eigenmodes: PT vs NT in “TCV”

TAE instability (radial mode structure of the electrostatic potential). Left: positive triangularity. Right: negative triangularity.

Alfven Eigenmodes: PT vs NT in “TCV”

TAE instability (frequency evolution, continuum, total EP density). Left: positive triangularity. Right: negative triangularity. Continuum obtained with Falcon (rad. coordinate to be checked).

Alfven Eigenmodes in NT “TCV”

Left: Tf/Te=40. Right: Tf/Te=100.

Alfven Eigenmodes in NT “TCV”

Left: Tf/Te=40. Right: Tf/Te=100.

EM Turbulence

Left: positive triangularity. Right: negative triangularity.
β=0.4%

EM Turbulence: energy flux

Left: positive triangularity. Right: negative triangularity.
Large zonal flows at the resonance q=4/3?

Conclusions

  • Multiple TAEs/EPMs and EM turbulence have been successfully simulated in TCV plasma using global gyrokinetic code ORB5

  • Synergy between TSVV2 and TSVV10

  • Validation exercises shall follow