ENERGY BALANCE OF AN ARC DISCHARGE IN HYDROGEN GAS

Presented are numerical calculations of the temperature and the pressure profiles and the voltage-current characteristic of a cylindrical arc column with an applied axial magnetic field. A radial pressure gradient is established by means of ambipolar diffusion of charged particles across the magnetic field and by means of the Nernst-Ettinghausen effect. Radiation losses are neglected. The dissociation of hydrogen molecules is taken into account, which has a great influence on the temperature profile and on the dissipated power if the axial temperature is not too high (<105 degrees K) Neglecting dissociation, as is often done, can lead to serious errors. The effect of the magnetic field on the dissipated power and the temperature profile is discussed.