[en] A great number of engineering problems about nuclear fusion have to be solved before it's real life application in energy generation be economically reasonable. Tokamaks are presently the most successful apparatus in magnetic confinement of plasma and performing the nuclear fusion. The control of the plasma position is one of the basic necessities in proper working of Tokamaks. Having a relatively precise model of the position variations with respect to control voltages is compulsory in the design of appropriate controllers. In this paper a simple model of the plasma position in Damavand Tokamak has been presented and then the stability of the closed loop system is investigated in the presence of uncertainties in the plasma as well as the controller parameters