Heat Transfer from Plasma to Solid Wall with Potential Difference

抄録

To investigate the influence of the electric potential on the heat transfer from a plasma to a solid wall, the heat input rates to the water-cooled Cu-pipe in an atmospheric pressure argon plasma jet were measured applying the potential difference ranging from -20 V to 5 V between the plasma and the pipe. The electric currents to the Cu-pipe were measured at the same time. It was found that in the lower potential difference the heat input rates are proportional to the currents and the proportional coefficient coincides with the work function of copper, but in the higher potential difference the heat input rates increase more due to the joule heating in the low temperature region about the pipe. It was also shown that the minimum point of the heat input rates is recognized at a slightly negative potential with respect to the floating potential.