Six thermophysical properties of both the solid and liquid zirconium measured using the high-temperature electrostatic levitator at JPL are presented. These properties are: density, thermal expansion coefficient, constant pressure heat capacity, hemispherical total emissivity, surface tension and viscosity. For the first time, we report the densities and the thermal expansion coefficients of both the solid as well as liquid Zr over wide ranges of temperatures. Over the 1700 -2300 K temperature

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... pan, the liquid density can be expressed as pl(T) = 6.24 x Id -0.29 (T -T, ) kg/m3 with Tm = 2128 K. and the corresponding volume expansion coefficient as a1 = 4.6 x /K. Similarly, over the 1250 -2100 K range, the measured density of the solid can be expressed as ps(T) = 6.34 x 103 -0.15 (T -Tm), giving a volume expansion coefficient as = 2.35 x /K. The constant pressure heat capacity of the liquid phase could be estimated as Cpl(T) = 39.72 -7.42 x (T -Tm) J/mol/K if the hemispherical total emissivity of the liquid phase remains constant at 0.3 over the 1825 -2200 K range. Over the 1400 -2100 K temperature span, the hemispherical total emissivity of the solid phase could be rendered as qs(T) = 0.29 -9.91 x I d (T -T",). The measured surface tension and the viscosity of the molten zirconium over the 1850 -2200 K range can be expressed as o(T) = 1.459 x I d -0.244 (T -T& mN/m and as q(T) = 4.83 -5.31 x 10-3(T -Tm) mPa.s, respectively.