Coupling the UEDGE plasma model and EIRENE neutrals model

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:489392

Rensink, M E; Rognlien, T D ^[1]; Coster, D P ^[2]

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1. Lawrence Livermore National Lab., CA (United States)
2. Max-Planck Institute for Plasma Physics, Garching (Germany)

For simulation of tokamak divertors, a fluid neutrals model may be appropriate in highly collisional regimes, whereas a kinetic model may be appropriate in collisionless regimes, whereas a kinetic model may be appropriate in collisionless regimes. In this report we investigate techniques for supplementing the fluid neutrals model in UEDGE with the EIRENE Monte Carlo neutrals model. We examine both steady-state and time-dependent coupling methods in which the EIRENE code calculates the plasma source terms for particles, parallel momentum, and electron and ion energy arising from interaction with neutral gas. For steady state modeling, the finite radius of convergence of the Newton-like method for the plasma update dictates that the plasma not be too far from the final solution. It may be possible to partially relax this constraint by incorporating a Jacobian derived from a fully implicit fluid model for both plasma and neutrals, while using the source terms from the Monte Carlo code to define residuals. For time-dependent simulations, the explicit nature of the plasma-neutral coupling limits the size of the time step for which the iteration will converge. This constraint might also be relaxed somewhat by using a Jacobian for the plasma update that is based on a fully implicit fluid model. Some degree of implictness can also be introduced by scaling the plasma source terms from EIRENE during a plasma update, e.g., with the ion current to the divertor plates. Results from a simulation with simple cartesian geometry will be presented.

• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 489392
• Report Number(s): CONF-960354--
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
99 GENERAL AND MISCELLANEOUS
DIVERTORS
E CODES
FLOW MODELS
MONTE CARLO METHOD
PLASMA SIMULATION
TOKAMAK DEVICES
U CODES