An advanced heat removal scenario is required to handle the highinput power of magnetic fusion reactors. The concepts of gas target and radiative divertorshave been explored. A set ofself-consistently coupled fluid equations for plasma and neutralsis suitable for this system because of the sophisticated equationsfor neutrals. The transfer of plasma momentum to neutrals, whichis crucial in understanding the plasma-neutral interface, isdescribed through the charge exchange process. Our code resultsshow good agreement with gas target experiments on the PISCES experiment anddemonstrate its superiority to the previous simulation. Thisbenchmarked code and a set of equations have been applied to aslot divertor for DEMO reactor. The slot length for the divertor can bedetermined by producing enough frictional force to overcome thethermal force which creates a backflow of impurities. A smallamount of radiating argon is enough to exhaust 40 MW of power fromthe core plasma in a 40 cm long slot for the inner divertor of DEMO.