Patent ID: 7276140

Claim:
A plasma accelerating apparatus comprising: a circular channel comprising an inner wall, an outer wall spaced apart from the inner wall by a distance for encircling the inner wall, and an end wall connected to an end of the inner wall and an end of the outer wall to form an outlet port at the other ends of the inner and outer walls; a gas supply portion which is configured to supply a gas to an inside of the channel; and a plasma generating and accelerating portion which is configured to supply ionization energy to the gas inside the channel to generate a plasma beam, and to accelerate the generated plasma beam toward the outlet port, wherein at least one of the inner wall and outer wall of the channel is inclined at an angle so that the other end of the at least one of the inner wall and outer wall is located closer to a center of the plasma accelerating apparatus, and wherein the plasma generating and accelerating portion comprises: an upper inductor disposed at an outer periphery in an axial direction of the end wall of the channel; an inner inductor disposed at a radial inside of the inner wall to reduce an induction magnetic field in an axial direction in the channel; and an external inductor disposed at a radial outside of the outer wall parallel with the internal inductor to reduce an induction magnetic field in an axial direction in the channel.