Seebeck coefficient measurements on Li, Sn, Ta, Mo, and W

The thermopower of W, Mo, Ta, Li and Sn has been measured relative to stainless steel, and the Seebeck coefficient of each of these materials has then been calculated. These are materials that are currently relevant to fusion research and form the backbone for different possible liquid limiter concepts including TEMHD concepts such as LiMIT. For molybdenum the Seebeck coefficient has a linear rise with temperature from SMo = 3.9 μV K−1 at 30 °C to 7.5 μV K−1 at 275 °C, while tungsten has a linear rise from SW = 1.0 μV K−1 at 30 °C to 6.4 μV K−1 at 275 °C, and tantalum has the lowest Seebeck coefficient of the solid metals studied with STa = −2.4 μV K−1 at 30 °C to −3.3 μV K−1 at 275 °C. The two liquid metals, Li and Sn have also been measured. The Seebeck coefficient for Li has been re-measured and agrees with past measurements. As seen with Li there are two distinct phases in Sn also corresponding to the solid and liquid phases of the metal. In its solid phase the SSn-solid = −1.5 μV K−1 at 30 °C and −2.5 μV K−1 near the melting temperature of 231 °C. There is a distinct increase in the Seebeck coefficient around the melting temperature as the Sn melts and stays relatively constant over the rest of the measured temperatures, SSn-melt = −1.4 μV K−1 from 235 °C to 275 °C.