Effect of fast plasma flows on volume recombination including MAR in detached divertor plasma

The effect of fast plasma flows on volume recombination including molecular activated recombination (MAR) in detached divertor plasma is theoretically investigated by solving particle balance equations for plasma, neutral particles, and ions. In the calculation model, the divertor region is divided into two regions, namely, region I with a high electron temperature of 10 eV and region II with a low electron temperature of 1 eV. The ion temperatures are assumed to be equal to the electron temperatures. When the plasma flows are not sufficiently slowed, for example, for plasma Mach numbers of M = 0.7 in region I and M = 0.5 in region II, the plasma sink due to volume recombination is less than 10% of the ion flux into region II. This means that volume recombination cannot contribute to the sink of ion fluxes even with the effect of MAR. The effects of the characteristic length of region II and the H₂ temperature on MAR are also discussed.