2011 年 29 巻 3 号 p. 27s-30s
Fe nanoparticles were generated by DC arc plasma method under atmospheric He-H2 mixture gas with different H2 concentration. The arc plasma was well constricted due to thermal pinching when H2 was mixed. The generation rate of the Fe nanoparticles significantly enhanced as H2 concentration increased to 40 %, and it was about 0.16 g/min for He-40 % H2 arc plasma. The vaporization rate of Fe did not significantly increase any more as H2 concentration exceeds 40 %. Numerical simulation based on magnetohydrodynamics (MHD) was performed and indicated that the Fe anode can be efficiently heated due to the H2 induced thermal pinching. The maximum anode temperature was calculated close to boiling point of Fe when heated by He-40 % H2 arc plasma. The specific surface area of Fe nanoparticles produced from He-40 % H2 arc plasma was about 11.7 m2/g and its corresponding diameter was 65 nm.
