Edge Plasma Physics: Key Considerations for PIC Codes & Simulations

[LuisVela]

Hello everybody.
Im starting a project on the basic processed undergoing in the edge plasma region. ( I mean, near the walls of a plasma confining device, like a tokamak or so.)

I was wondering if you could name some ''things'' I should be aware of in order to make a small PIC code or computer simulation.

I came up with these ones:

1.) Electron sheath on the walls, and over diagnostic devices (Probes and so on..).

2.) Non-Maxwellian distribution near the edge.

3.) High gradients on temperature & electric potential.

4.) In case of a PIC code, be awarer that the electron-larmor radius is bigger than the dimensions of the cell composing the grid.

...any suggestions?

 

[Astronuc]

There would be a greater density of neutrals near the edge of the plasma. If the plasma (neutral) make it to the wall, then there are spallation reactions with the wall, and that is the source of contamination (of higher Z atoms) in the plasma. If the current density is greater in the sheath, then the sheath temperature is higher and the heat must be conducted to the interior.

The heating might also be accomplished by neutral beam injection, microwave heating and compression.

 

[raining Pete]

Hi there! Your project sounds really interesting. I'm not an expert in this field, but I did some research and here are a few more things that you might want to consider for your PIC code or simulation:

1. Ionization and recombination processes: Since you're focusing on the edge plasma region, it's important to take into account the ionization and recombination processes that occur near the walls. These processes can significantly affect the plasma density and composition.

2. Neutral gas interactions: The edge plasma region is also where the plasma interacts with neutral gas, which can have a significant impact on the plasma behavior. You might want to consider including neutral gas interactions in your simulation.

3. Plasma instabilities: The edge plasma region is prone to various instabilities, such as edge localized modes (ELMs) and edge pedestal instabilities. These can have a major impact on the plasma confinement and should be included in your simulation.

4. Boundary conditions: It's important to carefully consider the boundary conditions for your simulation, especially in the edge region where the plasma is in contact with the walls. These conditions can significantly affect the accuracy of your results.

I hope these suggestions are helpful. Good luck with your project!