114 巻 (1994) 12 号 p. 869-874
The mean temperature of central region of the arc for producing fullerene molecules is estimated through the following procedure. First, particle densities of carbon vapor-helium mixture gas are calculated as a function of temperature for various carbon mixture ratios, assuming local thermal equilibrium. From those particle densities, the spectral power-wavelength characteristics (spectral power profiles) are calculated for various temperatures of 3, 000 to 15, 000K and for various carbon mixture ratios of 10 to 100%. The results show that the spectral power of C2 is stronger than that of C+ in the temperature range from 3, 000 to 9, 000 K at a constant carbon mixture ratio of 50%, and that the latter is stronger than the former in the carbon mixture ratio from 10 to 30% at a constant temperature of 9, 000K whereas the former is stronger than the latter in the carbon mixture ratio from 50 to 100%.
Next, the spectral intensity profile of the arc (DC 170 A, graphite electrodes, gap length: 3mm, He, 10kPa) is measured with a monochromator. Then, by comparing the measured spectral intensity profile with the calculated spectral power profiles, the mean temperature of central region of the arc and the carbon mixture ratio are estimated to be 7, 000 to 9, 000K and 80 to 100%, respectively.