The origin of Bohm diffusion, investigated by a comparison of different modelling methods

E Bultinck (1) , S Mahieu (2) , D Depla (2) , A Bogaerts (1)

1 Department of Chemistry
2 Department of Solid State Sciences

" Bohm diffusion " causes the electrons to diffuse perpendicular to the magnetic field lines. However, its origin is not yet completely understood: low and high frequency electric field fluctuations are both named to cause Bohm diffusion. The importance of including this process in a Monte Carlo (MC) model is demonstrated by comparing calculated ionization rates with particlein-cell/Monte Carlo collisions (PIC/MCC) simulations. A good agreement is found with a Bohm diffusion parameter of 0.05, which corresponds well with experiments. Since the PIC/MCC method accounts for fast electric field fluctuations, we conclude that Bohm diffusion is caused by fast electric field phenomena.

Mots clés: Physical Sciences

E Bultinck, S Mahieu, D Depla, A Bogaerts. The origin of Bohm diffusion, investigated by a comparison of different modelling methods. Journal of Physics D: Applied Physics, 2010, 43 (29), pp.292001. ⟨10.1088/0022-3727/43/29/292001⟩. ⟨hal-00569653⟩