The affection of magnetic field on the axial motion of a rotating electric arc

Summary form only given. A magnetic field is often used to rotate an electric arc in thermal plasma generators. Experimental results have shown that such a magnetic field also affects the axial motion of the arc spots. A new formula for the axial magnetic field force on an electric arc is derived from the knowledge about the interaction of charged particles and magnetic field. It is shown that the magnetic field draws the arc spot to its center at the cathode and pushes the arc spot away at the anode