Temperature and radiant power emitted from DC horizontal short free arc discharge mixtured with tungsten vapor

The temperature of the arc discharge in air was measured by the spectrometer and the radiant power of the DC horizontal free arc between tungsten electrodes was measured with a spectroscope and a power meter at 20-50 A of the arc current, 0.1 MPa in pressure. As a result, it was calculated that the W I was bigger than the nitrogen spectral line N I when the temperature was less than 10,000 K. The total radiant power density is estimated to be about 10/sup 10/ W/(m/sup 3/sr) at 6,000-10,000 K, 38-5030000 nm in wavelength region. The radiant power density emitted from W I is higher than N I, N II, O I, O II. The radiant power, /spl Phi/(W) (300 nm-30 /spl mu/m), in case of the point light source of radiant power emitted from DC horizontal short free arc discharge mixtured tungsten vapor as functions of current, 860 W(30 A) 1,480 W(50 A)2,100 W(70 A), and increase in proportion to the 1.06th power of the current. This value is more less than wall-stabilized arc The radiant energy /spl Phi//sub E/(kJ)(300 nm-30 /spl mu/m) in case of the point light source of radiant Power emitted from DC horizontal short free arc discharge mixtured Tungsten Vapor as functions of current and in-put energy is 27 kJ(35 kJ), 35 kJ(45 kJ), 43 kJ(55 kJ), and increase in proportion to the 1.06th power of the in-put power. The radiant efficiency is extremely high level about 80% as white light. This value is considered as champion data, because it is double than gases only The temperature of free arc mixtured tungsten is estimated about 5,500 K-5,600 K at 30, 50, 70 A by using line pair method. These temperatures are almost same value even if the current changes When the current increases, the effect of arc expanse to radius direction is stronger than increment of temperature in case of free arc It is considered that the energy of arc becomes the increment. of radius, because there are no influences of the wall and the gases for radius The radiant power increases in proportion to the 1.06th po- er of the current. This value is half of the wall-stabilized arc Because the free arc doesn´t have the restriction of radius, the radius increases to expand to radius direction. The arc radius increases in proportion to the square root of the current in case of constant of current density.