Solar thermal testing of ablators and composites

An apparatus for thermal ablation testing, the apparatus comprising:

• a chamber with an optically transparent window;
• a test sample in a sample holder inside the chamber;
• a mass balance inside the chamber, wherein the mass balance is configured to hold the sample holder and dynamically detect changes in mass of the test sample;
• a number of wire thermocouples connected to the test sample, wherein the wire thermocouples generate temperature data in the form of voltage;
• a vacuum pump connected to the chamber, wherein the vacuum pump is configured to control atmospheric pressure within the chamber;
• a mass-flow controller connected to the chamber, wherein the mass-flow controller is configured to pump a purge gas into the chamber;
• an external radiant heat source configured to heat the test sample through the window;
• a water-cooled heat shield within the chamber between the test sample and radiant heat source, wherein the heat shield comprises an aperture through which the test sample is exposed to the radiant heat source;
• and
• a pyrometer directed at the test sample.

A method of thermal ablation testing, the method comprising:

• placing a test sample in a sample holder, wherein the sample holder is located inside a chamber;
• heating the test sample, through an optically transparent window in the chamber, with an external radiant heat source, wherein the radiant heat source generates a heat flux of 50 to 6000 kW/m2;
• detecting temperature data in the form of voltage generated by a number of thermocouples connected to the test sample;
• dynamically detecting changes in mass of the test sample with a mass balance inside the chamber, wherein the mass balance is configured to hold the sample holder;
• and
• measuring surface temperature of the test sample with a pyrometer directed at the test sample.