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The least pressure for calculating the plasma

Posted Mar 18, 2018, 4:34 p.m. EDT Plasma Physics, Parameters, Variables, & Functions Version 5.3a 1 Reply

Luigi Lusini
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Dear Specialists!

I would like to know what least pressure (vacuum) can be used in Plasma Modul.

Thanks and Regards

1 Reply Last Post Mar 20, 2018, 8:32 a.m. EDT
Daniel Smith COMSOL Employee

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Posted: 7 years ago Mar 20, 2018, 8:32 a.m. EDT

Hi Luigi, the exact answer also depends on what the characteristic geometry size is. For the fluid approximation (which is what COMSOL uses for the plasma) to be valid, the plasma must be collisional. Therefore the electron-neutral mean free path must be much smaller than the characteristic geometry size. So, for a reactor size on the order of centimeters, the pressure must be above around 20mtorr.

Hi Luigi, the exact answer also depends on what the characteristic geometry size is. For the fluid approximation (which is what COMSOL uses for the plasma) to be valid, the plasma must be collisional. Therefore the electron-neutral mean free path must be much smaller than the characteristic geometry size. So, for a reactor size on the order of centimeters, the pressure must be above around 20mtorr.

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