| Abstract: | Some characteristic data are recorded for a nitrogen plasma jet design of the wall stabilized type incorporating a strongly and a poorly cooled tungsten hollow anode insert for currents between 133 and 175 A and mass flow rates between 0.94 and 1.54 g/s N2. From the characteristic data, conclusions are drawn relative to the anode behavior in dependence from the cooling conditions. The results especially of the calorimetric measurements and of the survey spectrum photographs indicate that the anode root area is greater in the case of the poorly cooled anode with the higher mean working temperature, and that in this case more heat at a lower level of heat flow density is transferred from the plasma to the anode body. The voltage oscillogramms indicate that even in the case of the poorly cooled anode the anode root is of the moving spot type, and that a transformation into the spotless immovable anode root has not yet been arrived. This will be attributed to the relative low level of the mean anode temperature even in the case of the poorly cooled anode for which estimations give values of below 2000 K. |
