DETERMINATION OF TRANSPORT FUNCTIONS FROM CHARACTERISTICS OF CYLINDRICAL ARCS (HYDROGEN)

On a stationary and cylindersymmetrical arc produced in a cascade arc chamber measurements are performed in order to determine the transport coefficients of the H2-plasma especially the electrical conductivity σ and the heat flux potential {Mathematical expression} T=temperature, κ=thermal conductivity). In a channel of 2 mm diam. and at a pressure of 1 atm. a wall-load of 19 kW/cm2 and an almost complete ionization were reached. The E-I-characteristic was measured for H2 in a wide range of arc currents. Because of technical and physical difficulties the total E-I-characteristic had to be composed of measurements taken from three different channel diameters and converted by scaling laws to the smallest diameter. After this reduction an effective current range from 5·10-2 A to 150 A is covered. For the measurement of the characteristics a quasistatic method was developed which is more precise than others used before. From the measured E-I-characteristic the radial distributions of the transport coefficients with the arc current I as parameter were computed exactly by means of the energy balance equation using a newly developed iteration procedure. The final result is the σ(S)-function of hydrogen. © 1969 Springer-Verlag.