# Low-frequency linear-mode regimes in the tokamak scrape-off layer

## Abstract

Motivated by the wide range of physical parameters characterizing the scrape-off layer (SOL) of existing tokamaks, the regimes of low-frequency linear instabilities in the SOL are identified by numerical and analytical calculations based on the linear, drift-reduced Braginskii equations, with cold ions. The focus is put on ballooning modes and drift wave instabilities, i.e., their resistive, inertial, and ideal branches. A systematic study of each instability is performed, and the parameter space region where they dominate is identified. It is found that the drift waves dominate at high R/L{sub n}, while the ballooning modes at low R/L{sub n}; the relative influence of resistive and inertial effects is discussed. Electromagnetic effects suppress the drift waves and, when the threshold for ideal stability is overcome, the ideal ballooning mode develops. Our analysis is a first stage tool for the understanding of turbulence in the tokamak SOL, necessary to interpret the results of non-linear simulations.

- Authors:

- Ecole Polytechnique Federale de Lausanne (EPFL), Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, CH-1015 Lausanne (Switzerland)

- Publication Date:

- OSTI Identifier:
- 22068869

- Resource Type:
- Journal Article

- Journal Name:
- Physics of Plasmas

- Additional Journal Information:
- Journal Volume: 19; Journal Issue: 11; Other Information: (c) 2012 EURATOM; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1070-664X

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BALLOONING INSTABILITY; ELECTROMAGNETIC RADIATION; EQUATIONS; IONS; MATHEMATICAL SPACE; NONLINEAR PROBLEMS; PLASMA DRIFT; PLASMA SCRAPE-OFF LAYER; PLASMA SIMULATION; STABILITY; TOKAMAK DEVICES; TURBULENCE; WAVE PROPAGATION

### Citation Formats

```
Mosetto, Annamaria, Halpern, Federico D., Jolliet, Sebastien, and Ricci, Paolo.
```*Low-frequency linear-mode regimes in the tokamak scrape-off layer*. United States: N. p., 2012.
Web. doi:10.1063/1.4758809.

```
Mosetto, Annamaria, Halpern, Federico D., Jolliet, Sebastien, & Ricci, Paolo.
```*Low-frequency linear-mode regimes in the tokamak scrape-off layer*. United States. doi:10.1063/1.4758809.

```
Mosetto, Annamaria, Halpern, Federico D., Jolliet, Sebastien, and Ricci, Paolo. Thu .
"Low-frequency linear-mode regimes in the tokamak scrape-off layer". United States. doi:10.1063/1.4758809.
```

```
@article{osti_22068869,
```

title = {Low-frequency linear-mode regimes in the tokamak scrape-off layer},

author = {Mosetto, Annamaria and Halpern, Federico D. and Jolliet, Sebastien and Ricci, Paolo},

abstractNote = {Motivated by the wide range of physical parameters characterizing the scrape-off layer (SOL) of existing tokamaks, the regimes of low-frequency linear instabilities in the SOL are identified by numerical and analytical calculations based on the linear, drift-reduced Braginskii equations, with cold ions. The focus is put on ballooning modes and drift wave instabilities, i.e., their resistive, inertial, and ideal branches. A systematic study of each instability is performed, and the parameter space region where they dominate is identified. It is found that the drift waves dominate at high R/L{sub n}, while the ballooning modes at low R/L{sub n}; the relative influence of resistive and inertial effects is discussed. Electromagnetic effects suppress the drift waves and, when the threshold for ideal stability is overcome, the ideal ballooning mode develops. Our analysis is a first stage tool for the understanding of turbulence in the tokamak SOL, necessary to interpret the results of non-linear simulations.},

doi = {10.1063/1.4758809},

journal = {Physics of Plasmas},

issn = {1070-664X},

number = 11,

volume = 19,

place = {United States},

year = {2012},

month = {11}

}