MOVEMENT IN PLASMA

• Drift - caused by electric field
• Diffusion - caused by the gradient in concentration/pressure
  • Electrons are faster, therefore they are first to reach for example a floating surface in the chamber, thus they charge negatively any surface
  • Subsequently electrons are repelled by the negative surface (negative in relation to the plasma potential) and ions are attracted to the surface
  • At equilibrium, an electric field is created by the positive and negative charges
• V_p - plasma potential (the potential that plasma has in relation to a grounded surface)
• V_F - floating potential
• the potential of a surface floating (without any applied bias, not grounded) in the plasma
• depends on the ion mass and electron tempreature: