B. F. McMillan

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A global plasma turbulence simulation code, ORB5, is presented. It solves the gyrokinetic electrostatic equations including zonal flows in axisymmetric magnetic geometry. The present version of the code assumes a Boltzmann electron response on magnetic surfaces. It uses a Particle-In-Cell (PIC), δf scheme, 3D cubic B-splines finite elements for the field(More)
Highly variable flux surface averaged heat fluxes are resolved in gyrokinetic simulations of ion temperature gradient ͑ITG͒ turbulence, even in large systems. Radially propagating fronts or avalanches are also seen. Their propagation lengths in gyroradii and relative amplitude remain constant as simulation size is increased, so the avalanches appear to(More)
—The particle-in-cell code ORB5 is a global gyroki-netic turbulence simulation code in tokamak geometry. solves the gyrokinetic equations in the whole plasma core, including the magnetic axis. A field-aligned filtering procedure and sophisticated noise-control and heating operators allow for accurate simulations. Recently, the code ORB5 has been extended to(More)
In this work, a Fourier solver [McMillan et. in order to reduce the memory of the matrix associated with the field equation. This scheme is verified with linear and nonlinear simulations of turbulence. It is demonstrated that the straight-field-line angle is the coordinate that optimizes the Fourier solver, that both linear and nonlinear turbulent states(More)
The eigenmode spectrum is a fundamental starting point for the analysis of plasma stability and the onset of turbulence, but the characterization of the spectrum even for the simplest plasma model, ideal magnetohydrodynamics (MHD), is not fully understood. This is especially true in configurations with no continuous geometric symmetry, such as in a real(More)
The constraint of incompressibility is often used to simplify the magnetohydrody-namic (MHD) description of linearized plasma dynamics because it does not affect the ideal MHD marginal stability point. In this paper two methods for introducing incompressibility are compared in a cylindrical plasma model: In the first method, the limit γ → ∞ is taken, where(More)
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