# GS2 Fusion Plasma Simulation#

## Overview#

This model uses GS2 to study plasma in a spherical tokamak; the simulation has been configured to use the gyrokinetic framework. It aims to study various modes in the plasma due to microinstabilities. As opposed to finding all available unstable modes, the current setup terminates once an unstable mode is found. Otherwise, it will continue running until reaching a fixed timestep. Therefore, the runtime varies depending on the input parameters.

## Run#

```
docker run -it -p 4242:4242 linusseelinger/model-gs2:latest
```

## Properties#

Model |
Description |
---|---|

forward |
Plasma simulation with the gyrokinetic model |

### forward#

Mapping |
Dimensions |
Description |
---|---|---|

input |
[2] |
[ |

output |
[3] |
[Electron heat flux, electric field growth rate, electric field mode frequency] |

Feature |
Supported |
---|---|

Evaluate |
True |

Gradient |
False |

ApplyJacobian |
False |

ApplyHessian |
False |

Config |
Type |
Default |
Description |
---|---|---|---|

ranks |
int |
1 |
MPI ranks to run the model |

## Mount directories#

Mount directory |
Purpose |
---|---|

None |

## Source code#

## Description#

GS2 is developed to study low frequency turbulence in magnetised plasma. In this benchmark, it solves the gyrokinetic Vlasov-Maxwell system of equations that are widely adopted to describe the turbulent component of the electromagnetic fields and particle distribution functions of the species present in a plasma. The problem is five-dimensional and takes the form

where \(F_a = F_a(\vec{x}, v_{\parallel}, \mu)\) is the 5D phase space gyrocenter distribution function for species \(a\), \(\frac{\partial \vec{X}}{\partial t} = \vec{v}\) is the particle velocity, \(\vec{x}\) is the three dimensional vector describing the guiding centre of a particle, \(v_{\parallel}\) is the velocity along the magnetic field line and \(\mu = v^2_{\perp}/2B\) is the magnetic moment, where \(v_{\perp}\) is the velocity perpendicular to the magnetic field and \(B\) is the magnetic flux density.

The above text was taken from the paper by Hornsby et al. (2023) which contains a more detailed description of the problem.