Automated rapid cooling of high-temperature vacuum furnaces for high throughput neutron experimentation

Experiments utilizing neutrons to characterize material microstructures and properties are regularly performed at neutron beamline facilities at temperatures up to 1500 °C and above. In the standard blue series top-loading furnace, the post-experiment cooldown relying purely on radiation cooling can take 2-3× longer than the test itself, leading to a significant loss of neutron beam time and low experimental throughput. Here, we present an automated rapid cooling technique that reduces the cooldown time for a high-thermal-mass sample from 500 to 100 °C by a factor of over 20 without significant impact on the furnace components. The cooling system has been extensively tested at the SNS facility at ORNL and demonstrated under an in situ neutron diffraction experiment at the VULCAN beamline. The system demonstrates rapid in situ cooling from 1500 to 100 °C in <12 min, validated by neutron diffraction data, along with the ability to perform automated thermal heating and cooling cycles with minimal user interaction. The utilization of the new cooling capability identifies discrepancies between the thermocouple and neutron diffraction-derived temperature measurements during fast heating and cooling, indicating a need to account for temperature measurement accuracy limitations during experimental design planning. The cooling system shows the potential to significantly increase experimental throughput by reducing the post-experiment cooling time while also enabling controllable temperature profiles by automating key aspects of the heat-up and cool-down processes.