Thermophysical properties of tungsten electrodes by subsecond pulse calorimetry

Prediction of the behavior of tungsten electrode material in high-temperature plasma generators requires knowledge of its thermophysical properties over a wide temperature range. For determination of its relevant thermophysical properties, the direct pulse heating calorimetry technique was chosen as the most appropriate, as it meets requirements of both high-speed measurements and the widest temperature range. As a high-temperature sensor, the method used simultaneously a fine-gauge thermocouple and an optical pyrometer. Such a combination enables coverage of a few thousand degrees within a second, with a time resolution of less than 1 ms. The measurement technique and details of the apparatus as well as experimental results for specific heat, electrical resistivity, normal spectral, and hemispherical total emittance in the temperature range from 300 to 2500 K are presented.Paper presented at the Fourth International Workshop on Subsecond Thermophysics, June 27–29, 1995, Köln, Germany.