## Simulation of neoclassical transport with the continuum gyrokinetic code COGENT

## Abstract

The development of the continuum gyrokinetic code COGENT for edge plasma simulations is reported. The present version of the code models a nonlinear axisymmetric 4D (R, v∥, μ) gyrokinetic equation coupled to the long-wavelength limit of the gyro-Poisson equation. Here, R is the particle gyrocenter coordinate in the poloidal plane, and v∥ and μ are the guiding center velocity parallel to the magnetic field and the magnetic moment, respectively. The COGENT code utilizes a fourth-order finite-volume (conservative) discretization combined with arbitrary mapped multiblock grid technology (nearly field-aligned on blocks) to handle the complexity of tokamak divertor geometry with high accuracy. Furthermore, topics presented are the implementation of increasingly detailed model collision operators, and the results of neoclassical transport simulations including the effects of a strong radial electric field characteristic of a tokamak pedestal under H-mode conditions.

- Authors:

- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

- Publication Date:

- Research Org.:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

- Sponsoring Org.:
- USDOE

- OSTI Identifier:
- 1248283

- Report Number(s):
- LLNL-JRNL-636187

Journal ID: ISSN 1070-664X; PHPAEN

- Grant/Contract Number:
- AC52-07NA27344

- Resource Type:
- Accepted Manuscript

- Journal Name:
- Physics of Plasmas

- Additional Journal Information:
- Journal Volume: 20; Journal Issue: 1; Journal ID: ISSN 1070-664X

- Publisher:
- American Institute of Physics (AIP)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 97 MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; 70 PLASMA PHYSICS AND FUSION; collision theories; electric fields; Lorentz group; tokamaks; plasma gyrokinetics

### Citation Formats

```
Dorf, M. A., Cohen, R. H., Dorr, M., Rognlien, T., Hittinger, J., Compton, J., Colella, P., Martin, D., and McCorquodale, P. Simulation of neoclassical transport with the continuum gyrokinetic code COGENT. United States: N. p., 2013.
Web. doi:10.1063/1.4776712.
```

```
Dorf, M. A., Cohen, R. H., Dorr, M., Rognlien, T., Hittinger, J., Compton, J., Colella, P., Martin, D., & McCorquodale, P. Simulation of neoclassical transport with the continuum gyrokinetic code COGENT. United States. doi:10.1063/1.4776712.
```

```
Dorf, M. A., Cohen, R. H., Dorr, M., Rognlien, T., Hittinger, J., Compton, J., Colella, P., Martin, D., and McCorquodale, P. Fri .
"Simulation of neoclassical transport with the continuum gyrokinetic code COGENT". United States. doi:10.1063/1.4776712. https://www.osti.gov/servlets/purl/1248283.
```

```
@article{osti_1248283,
```

title = {Simulation of neoclassical transport with the continuum gyrokinetic code COGENT},

author = {Dorf, M. A. and Cohen, R. H. and Dorr, M. and Rognlien, T. and Hittinger, J. and Compton, J. and Colella, P. and Martin, D. and McCorquodale, P.},

abstractNote = {The development of the continuum gyrokinetic code COGENT for edge plasma simulations is reported. The present version of the code models a nonlinear axisymmetric 4D (R, v∥, μ) gyrokinetic equation coupled to the long-wavelength limit of the gyro-Poisson equation. Here, R is the particle gyrocenter coordinate in the poloidal plane, and v∥ and μ are the guiding center velocity parallel to the magnetic field and the magnetic moment, respectively. The COGENT code utilizes a fourth-order finite-volume (conservative) discretization combined with arbitrary mapped multiblock grid technology (nearly field-aligned on blocks) to handle the complexity of tokamak divertor geometry with high accuracy. Furthermore, topics presented are the implementation of increasingly detailed model collision operators, and the results of neoclassical transport simulations including the effects of a strong radial electric field characteristic of a tokamak pedestal under H-mode conditions.},

doi = {10.1063/1.4776712},

journal = {Physics of Plasmas},

number = 1,

volume = 20,

place = {United States},

year = {2013},

month = {1}

}

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