Can detached divertor plasmas be explained as self-sustained gas targets?

Abstract

The gas target hypothesis is evaluated as an explanation for the detached plasma state that can occur under certain operating conditions in divertor tokamaks. For sufficiently low electron temperature of the divertor plasma the recycling neutrals could, via elastic and charge exchange collisions, cause sufficient momentum loss to the plasma flow towards the plate that the plasma outflow rate would be reduced for fixed upstream plasma conditions, i.e. the particle confinement time would be increased. The necessary conditions for the divertor plasma to form such a self-sustained gaseous target are considered