The article describes the Orange Cryostats (OCs) used at the National Center for Neutron Research (NCNR), which are based on a design originally developed by the Institut Laue-Langevin (ILL) in France. These cryostats are top-loading systems that allow users to control sample temperature by adjusting heater current and helium flow through a heat exchanger. The sample is mounted on a stick and placed in a helium-filled sample well, where temperature is regulated using a PID controller and manually adjusted valves.
The cryostats can operate down to 4.2 Kelvin using a warm valve, or even lower with a vacuum pump. They also allow for cryogen refilling during operation in pumping mode, though this uses more helium. Special setups for different experiments, such as gas handling or high-pressure measurements, are possible but require prior discussion with the sample environment staff. The OCs are versatile tools for a range of scientific experiments requiring precise temperature control.
Source: https://www.nist.gov/ncnr/sample-environment/equipment/liquid-helium-cryostats/orange-cryostats
Keywords: cryostats, helium exchange gas, sample mounting
