It is shown that non-ideal confinement of alpha particles in tokamak reactors should result in the generation of a longitudinal current in the plasma. The distribution of this current along the radius is studied in the case of tokamaks with relatively good alpha-particle confinement, and its relationship with the plasma parameters established. It is found that when the current generated by the plasma particles flows in the direction opposite to that of the original current in the plasma, the initial current should exceed some critical value for the steady states to exist. If it does not, the alpha particles will lead to a drop in the current in the plasma.
Confinement of alpha particles in tokamak reactors