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. Direct prediction of saturated neoclassical tearing modes in slab using an equilibrium approach
 
Loading...
Thumbnail Image
research article

Direct prediction of saturated neoclassical tearing modes in slab using an equilibrium approach

Balkovic, Erol  
•
Loizu, Joaquim  
•
Graves, Jonathan  
Show more
November 27, 2024
Plasma Physics and Controlled Fusion

We demonstrate for the first time that the nonlinear saturation of neoclassical tearing modes (NTMs) can be found directly using a variational principle based on Taylor relaxation, without needing to simulate the intermediate, resistivity-dependent dynamics. As in previous investigations of classical tearing mode saturation (Loizu et al. 2020; Loizu & Bonfiglio 2023), we make use of Stepped Pressure Equilibrium Code (SPEC) (Hudson et al. 2012), an equilibrium solver based on the variational principle of the Multi-Region relaxed MHD, featuring stepped pressure profiles and arbitrary magnetic topology. We work in slab geometry and employ a simple bootstrap current model J bs = C ∇p to study the bootstrap-driven tearing modes, scanning over the asymptotic matching parameter ∆ ′ and bootstrap current strength. Saturated island widths produced by SPEC agree well with the predictions of an initial value resistive Magnetohydrodynamics (MHD) code (Huang & Bhattacharjee 2016) while being orders of magnitude faster to calculate. Additionally, we observe good agreement with a simple analytical Modified Rutherford Equation, without requiring any fitting coefficients. The match is obtained for both linearly unstable classical tearing modes in the presence of bootstrap current, and neoclassical tearing modes, which are linearly stable but nonlinear-unstable due to the effects of the bootstrap current.

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

Balkovic+et+al_2024_Plasma_Phys._Control._Fusion_10.1088_1361-6587_ad97dd.pdf

Type

Main Document

Access type

openaccess

License Condition

CC BY

Size

1.01 MB

Format

Adobe PDF

Checksum (MD5)

a4197a5ee8b785e4c07ab70d8fd3944c

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