Abstract: | The non-equilibrium electrical conductivity and the relaxation of electron density in seeded plasma for MHD power generators were studied experimentally. The experiments were performed with use made of potassium seeded argon plasma (A+0.14%K) at 1,800°2,000°K, flowing in a rectangular duct at constant velocity (about 240m/sec) under atmospheric pressure. The dependence of the electrical conductivity on the electric current density was found to agree well with theoretical prediction based on the two-temperature model, if a value of 40 was chosen for the collision loss parameter. The effect of the radiative energy loss of potassium atoms was not significant in the present experiments. Furthermore, it was found that the relaxation of the electron density can be well expressed by the recombination coefficient for the electronic three-body recombination processes, and that the relaxation time is about 4 × 104 sec for the present experimental conditions. |