The temperature and radiant power emitted from DC horizontal short free arc discharge between tungsten electrodes near 50A

Summary form only given. The characteristics of the arc discharge have the high temperature and highly intense radiation. Therefore, the arc discharge is used for a lot of applications such as plasma torches, lighting, so far. When a reduction of the waste and dissolution of the iron are carried out by using a plasma arc discharge, the radiant power emitted from the plasma arc should be suppressed. In those cases it has to be precisely controlled. In this paper, the mass densities of the tungsten spectral line W(I) and W(II) are calculated. The temperature of the arc discharge in air was measured by the spectrometer and the radiant power of DC horizontal free arc between tungsten electrodes was measured with a spectroscope and a power-meter at 20-50A of the arc current, 0.1 MPa in pressure. The results of this paper are shown. 1) It was calculated that The W(I) was bigger than the nitrogen spectral line N(I) when the temperature was less than 10,000K. It was measured by the spectrometer that the tungsten spectral line W(I) domained from 400nm to 500nm. 2) The W(I) could be focused on to estimate the temperature. The temperature of the arc discharge was evaluated to be about 5,500K by the line pair method. 3) The measured radiant power was 160 mW at 50A by the power meter. The radiant power increased in proportion to 0.64th power of the current. The radius of the arc discharge could change easily, because it is a free arc discharge that is different from the wall-stabilized arc. Therefore, the temperature of the arc discharge was not depended on the free arc current, and the logarithmic slope of the radiant power to current was not so changed.