1D Fluid Regime of Plasma‐Neutral Interaction and Divertor Detachment

We show that self consistent decrease of both plasma flux and neutral ionization in current tokamaks is only possible when neutrals can be treated in a short mean free path approximation. We investigate these fluid regimes of plasma‐neutral interaction with 1D fluid equations employing a neutral viscosity term to treat the neutral interaction with the divertor plate. We have found that plasma flux onto the target starts to decrease at a very low heat flux coming into the hydrogen recycling region, when the temperature near the target drops below 1 eV, which seems lower than observed in the experiments. We conclude that the neutral‐neutral collisions, 2D effects of plasma‐neutral interaction, and plasma recombination processes can play a very important role in divertor plasma detachment.