dorsal/arxiv
View SchemaDynamics of resistive double tearing modes with broad linear spectra
| Authors | Andreas Bierwage, Sadruddin Benkadda, Satoshi Hamaguchi, Masahiro Wakatani |
|---|---|
| Categories | |
| ArXiv ID | physics/0609102 |
| URL | https://arxiv.org/abs/physics/0609102 |
| DOI | 10.1063/1.2446420 |
| Journal | Phys. Plasmas 14, 022107 (2007) |
Abstract
The nonlinear evolution of resistive double tearing modes (DTMs) with safety factor values q=1 and q=3 is studied in a reduced cylindrical model of a tokamak plasma. We focus on cases where the resonant surfaces are a small distance apart. Recent numerical studies have shown that in such configurations high-m modes are strongly unstable. In this paper, it is first demonstrated that linear DTM theory predicts the dominance of high-m DTMs. A semi-empirical formula for estimating the poloidal mode number of the fastest growing mode, m_peak, is obtained from the existing linear theory. Second, using nonlinear simulations, it is shown that the presence of fast growing high-m modes leads to a rapid turbulent collapse in an annular region, whereby small magnetic island structures form. Furthermore, consideration is given to the evolution of low-m modes, in particular the global m=1 internal kink, which can undergo nonlinear driving through coupling to fast growing linear high-m DTMs. Factors influencing the details of the dynamics are discussed. These results may be relevant for the understanding of the magnetohydrodynamic (MHD) activity near the minimum of q and may thus be of interest to studies concerned with stability and confinement in advanced tokamaks.
{
"annotation_id": "8bae277a-0f2e-443c-adbc-166a9caab0b1",
"date_created": "2026-03-02T18:01:11.263000Z",
"date_modified": "2026-03-02T18:01:11.263000Z",
"file_hash": "9c839ecfac44144c4347825c9c7a972c92c0ff76d042e2df9e75117eaff8976a",
"private": false,
"record": {
"abstract": "The nonlinear evolution of resistive double tearing modes (DTMs) with safety\nfactor values q=1 and q=3 is studied in a reduced cylindrical model of a\ntokamak plasma. We focus on cases where the resonant surfaces are a small\ndistance apart. Recent numerical studies have shown that in such configurations\nhigh-m modes are strongly unstable. In this paper, it is first demonstrated\nthat linear DTM theory predicts the dominance of high-m DTMs. A semi-empirical\nformula for estimating the poloidal mode number of the fastest growing mode,\nm_peak, is obtained from the existing linear theory. Second, using nonlinear\nsimulations, it is shown that the presence of fast growing high-m modes leads\nto a rapid turbulent collapse in an annular region, whereby small magnetic\nisland structures form. Furthermore, consideration is given to the evolution of\nlow-m modes, in particular the global m=1 internal kink, which can undergo\nnonlinear driving through coupling to fast growing linear high-m DTMs. Factors\ninfluencing the details of the dynamics are discussed. These results may be\nrelevant for the understanding of the magnetohydrodynamic (MHD) activity near\nthe minimum of q and may thus be of interest to studies concerned with\nstability and confinement in advanced tokamaks.",
"arxiv_id": "physics/0609102",
"authors": [
"Andreas Bierwage",
"Sadruddin Benkadda",
"Satoshi Hamaguchi",
"Masahiro Wakatani"
],
"categories": [
"physics.plasm-ph"
],
"doi": "10.1063/1.2446420",
"journal_ref": "Phys. Plasmas 14, 022107 (2007)",
"title": "Dynamics of resistive double tearing modes with broad linear spectra",
"url": "https://arxiv.org/abs/physics/0609102"
},
"schema_id": "dorsal/arxiv",
"source": {
"execution_id": "ef74161f-56c6-4baf-acd6-3930c9a681c5",
"id": "arXiv Dataset IDs",
"type": "Model",
"variant": "snapshot-2026-03-01",
"version": "0.1.0"
},
"user_id": 1000002
}