Thermoelectric properties of a plasma at megabar pressures

A nonideal hydrogen plasma is theoretically studied for the first time as the working medium of a thermoelectric generator. A method is proposed for the calculation of the electrical conductivity, Seebeck coefficient, and thermal conductivity of the nonideal plasma in a wide range of densities and temperatures, including the region of strong degeneracy of electrons, which is achieved in experiments on the quasi-isentropic compression of deuterium and where a “plasma phase transition” (transition with a sharp change in the component composition) is possibly implemented. In this method, the kinetic coefficients are calculated together with the equation of states of the nonideal plasma. It is shown for the first time that the Seebeck coefficient in such a medium reaches 5500 $\mu$V/(K cm), which is an order of magnitude larger than that in currently available semiconductor materials used in thermoelectric generators. It is found that the figure of merit in hydrogen, which has a high thermal conductivity, at megabar pressures reaches 0.4, which is only slightly below that in currently available semiconductor materials.