A novel approach to radially global gyrokinetic simulation using the flux-tube code stella

A novel approach to global gyrokinetic simulation is implemented in the flux-tube code $\texttt{stella}$. This done by using a subsidiary expansion of equation perpendicular scale length turbulence, originally derived Parra and Barnes [Plasma Phys. Controlled Fusion, $\textbf{57}$ 054003, 2015], which allows use Fourier basis functions while enabling effect radial profile variation be included perturbative way. Radial magnetic geometry utilizing extension Grad-Shafranov Miller equilibrium equations obtained through Taylor expansion. boundary conditions that employ multiple simulations are also developed, serving as more physically motivated replacement conventional Dirichlet used simulation. It shown these new eliminate much numerical artefacts generated near when expressing non-periodic function spectral basis. We then benchmark both linearly nonlinearly number standard test cases.