Interaction of helium ion beam with argon gas and plasma

A helium ion beam is extracted and is injected into an argon gas and a plasma in a linear device in terms of experimental study of interaction between energetic ions in divertor plasmas and gases for radiator. The beam with the energy of 0-10 keV passing through the argon gas is attenuated by charge-exchange and elastic collisions with increasing the filling gas pressure. The electron temperature (∼10 eV) and density (∼107 cm-3) of a bulk plasma degrade under the ion beam in some conditions. A beam-produced plasma is also observed. Although mechanism of the degradation is unresolved, the argon gas in the divertor is expected to moderate the momentum flux of energetic ion. (author)