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.

Authors¶

Chung Ming Loi

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]	[`tprim`: normalised inverse temperature gradient, `vnewk`: normalised species-species collisionality frequency]. Both are set for electrons only.
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
None

Mount directories¶

Mount directory	Purpose
None

Source code¶

Model sources here.

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

\[ \frac{\partial F_a}{\partial t} + \frac{\partial \vec{X}}{\partial t} \cdot \nabla F_a + \frac{\partial v_{\parallel}}{\partial t} \frac{\partial F_a}{\partial v_{\parallel}} = 0, \]

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.