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EUTERPE: Difference between revisions
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where the <math>w_p</math> are the weights (contribution to the distribution function) associated to each marker. | where the <math>w_p</math> are the weights (contribution to the distribution function) associated to each marker. | ||
The electric potential is represented on a spatial grid, the electric charge being carried by the markers. Two coordinate systems are used in the code: a system of magnetic coordinates (PEST) <math>(s, \theta,\phi )</math> is used for the electrostatic potential and cylindrical coordinates <math>(r, z,\phi )</math> are used for pushing the particles, where <math>s=\Psi / \Psi_0</math> is the normalized toroidal flux. The change between coordinate systems, which is facilitated by the existence of the common coordinate <math>(\phi)</math>, is done in a continuous way. The equation for the field is discretized using finite elements (B-splines) and the PETSc library is used for solving it. The integration of the motion is done using a fourth order Runge-Kutta scheme. | The electric potential is represented on a spatial grid, the electric charge being carried by the markers. Two coordinate systems are used in the code: a system of magnetic coordinates (PEST) <math>(s, \theta,\phi )</math> is used for the electrostatic potential and cylindrical coordinates <math>(r, z,\phi )</math> are used for pushing the particles, where <math>s=\Psi / \Psi_0</math> is the normalized toroidal flux. The change between coordinate systems, which is facilitated by the existence of the common coordinate <math>(\phi)</math>, is done in a continuous way. The equation for the field is discretized using finite elements (B-splines) and the PETSc library is used for solving it. The integration of the motion is done using a fourth order Runge-Kutta scheme. In linear simulations a phase factor transformation can be used and the equations can be integrated using a predictor-corrector scheme. These options have not been used in this work. | ||
An equilibrium state calculated with the code VMEC is used as a starting point. The equilibrium quantities computed by VMEC are mapped onto the spatial grid using an intermediate program. EUTERPE features several techniques for the noise control: the filtering of Fourier modes (square and diagonal filters can be used) and the optimized loading <ref>[http://pop.aip.org/phpaen/v9/i3/p898_s1 Hatzky, R Tran, TM Konies, A Kleiber, R Allfrey, SJ .Energy conservation in a nonlinear gyrokinetic particle-in-cell code for ion-temperature-gradient-driven modes in theta-pinch geometry. PHYSICS OF PLASMAS, 9- 3,p. 912,2002.]</ref>. More details about the code can be found in the Refs~\cite{EUTERPE:Jost,EUTERPE:Jost2,EUTERPE:Kornilov04,EUTERPE:Kornilov05,EUTERPE:Kleiber06} | An equilibrium state calculated with the code VMEC is used as a starting point. The equilibrium quantities computed by VMEC are mapped onto the spatial grid using an intermediate program. EUTERPE features several techniques for the noise control: the filtering of Fourier modes (square and diagonal filters can be used) and the optimized loading <ref>[http://pop.aip.org/phpaen/v9/i3/p898_s1 Hatzky, R Tran, TM Konies, A Kleiber, R Allfrey, SJ .Energy conservation in a nonlinear gyrokinetic particle-in-cell code for ion-temperature-gradient-driven modes in theta-pinch geometry. PHYSICS OF PLASMAS, 9- 3,p. 912,2002.]</ref>. More details about the code can be found in the Refs~\cite{EUTERPE:Jost,EUTERPE:Jost2,EUTERPE:Kornilov04,EUTERPE:Kornilov05,EUTERPE:Kleiber06} | ||