A System Employing Laser Heating for the Measurement of High-Temperature Thermal Properties Over a Wide Pressure Range.

An equipment system is described that can be used to obtain high-temperature physical property data on refractory materials by means of laser heating. Properties that can be measured are vapor pressure of solid and liquid phases relative rate of vaporization and emission spectra from solid and vapor phases. Solid phases can be studied by splat cooling of the liquid and quench cooling of the solid and vapor. Temperature can be measured both pyrometrically and spectroscopically. In addition, the effects produced by heating a material in an atmosphere of controlled composition and pressure can be studied. The equipment system described here was designed to obtain data on the phase behavior of carbon in the 3500 to 4700 K temperature range, a temperature range for which there is no material that can be used to contain carbon to measure vapor pressure, phase transitions, and melting point by the conventional methods. The CO2 laser was used for heating.