Gyrokinetic analysis of General Fusion’s Magnetized Target Fusion (MTF) Plasmas

General Fusion (GF) is developing a Magnetized Target Fusion concept toward commercial fusion power production [1]. In MTF, a spherical tokamak target plasma is formed by coaxial helicity injection into a liquid metal flux conserver and compressed rapidly to reach fusion-relevant conditions. Pi3 at GF is a non-compressing device with solid lithium walls used to improve MTF targets to design future machines.  In this work, we present the first thermal transport analysis of Pi3 plasmas using gyrokinetic simulations. Local gyrokinetic flux tube simulations are performed for Pi3 shot 18669 in the radial range r/a=0.2-0.8, with reduced quasilinear code TGLF [2] to simulate turbulence and NEO [3] to simulate neoclassical transport. These simulations indicate that ITG and TEM modes are the most unstable modes in the ion-scale range, with no electron scale ETG modes for r/a<0.3. However, for 0.3<r/a<0.8, ETG unstable modes are present. The dominant transport channels for turbulent heat losses are ITG and TEM modes at small wavenumber. Transport is neoclassical for r/a<0.2, and anomalous for r/a>0.2. The future goal of this work is to perform sensitivity analysis concerning plasma profiles and validate quasilinear TGLF fluxes with nonlinear gyrokinetic code CGYRO for GF plasma conditions.  

 

[1] M. Laberge, JFE 38, 199203 (2019)

[2] G.M. Staebler  et al., POP 14, 055909 (2007)

[3] E. A. Belli and J. Candy, PPCF 50, 095010 (2008)