Thermophysical properties by a pulse-heating reflectometric technique: Niobium, 1100 to 2700 K

Pulse-heating experiments were performed on niobium strips, taking the spec imens from room temperature to the melting point is less than one second. T he normal spectral emissivity of the strips was measured by integrating sph ere I reflectometry, and, simultaneously, experimental data (radiance tempe rature. cur rent, voltage drop) for thermophysical properties were collecte d with submillisecond time resolution. The normal spectral emissivity resul ts were used to compute the true temperature of the niobium strips; the hea t capacity, electrical resistivity, and hemispherical total emissivity were evaluated in the temperature range 1100 to 2700 K. The results are compare d with literature data obtained in pulse-heating experiments. It is conclud ed that combined measurements of normal spectral emissivity and of thermoph ysical properties on strip specimens provide results of the same quality as obtained using tubular specimens with a blackbody. The thermophysical prop erty results on niobium also validate the normal spectral emissivity measur ements by integrating sphere reflectometry.