Temperature dependence of the density and electrical resistivity of liquid zirconium up to $4100$ K

Experimental data on the temperature dependence of the density of liquid zirconium and its electrical resistivity are obtained under conditions of pulsed electric heating (for $5$ to $10\mu$s) of wire and foil zirconium samples. Samples in the form of a wedge-shaped blackbody model are prepared for use in temperature measurements. The thermal radiation from the model space is registered by a high-speed optical pyrometer at a wavelength of $855$ nm. The temperature (up to $4100$ K) is calculated by Planck's formula. The temperature plateau in the melting region of the blackbody model is used for calibration of the pyrometer. In so doing, it is assumed that this plateau has the equilibrium melting temperature of $2128$ K. A digital oscilloscope is used for recording the current through the sample, the voltage across the sample, and the pyrometer signal. The density of zirconium is determined using the laser flash method while heating zirconium wires. The sample is illuminated by a $Q$-switched Nd-YAG laser. A CCD video camera is used for photographing. The experimental data on the density and electrical resistivity of liquid zirconium are essential for simulation of the behavior of nuclear power plants in the case of a serious emergency.