ILL provides 23 furnaces that are available from a pool or assigned to instruments. The maximum allowable temperatures range from 250 to 1650°C. All repairs and modifications are carried out in the High-Temperature Laboratory.
Automated power crate
We have designed and constructed power crates for regulating automatically the sample tempertaure in resistive furnaces. They are much safer than the previous units and seven units are available. After inserting the sample, it suffices to start the pumping and enter a temperature setpoint. The PLC starts the primary pump, waits for the required vacuum pressure to start the turbo pump and the heating with one of the two power units (low and high-power modes). In case of degasing or temporary lack of cooling water, the PLC pauses the heating until one of the required conditions to heat is again satisfied. Of course, if that does not happen before a timeout period, the PLC stops operating the furnace and requires manual intervention.
Recently, we have upgraded these power racks to reduce the cool-down time by a factor of 4 to 5 without impacting the lifetime of the heated elements. The technique consists in injecting 75 ml of helium when the temperature falls to lower than 800 to 1000°C (depending on the furnace type). Users can enable or not this mode remotely from the instrument controller software. See J. Neutron Research 21, 3-4 (2019) 137-142.
Ultra-high Temperature and Aerodynamic levitation
We plan to supply in the coming years a furnace for reaching ultra-high temperatures (up to 3000 K). We have started building a prototype compatible with the use of polarised beams which can be installed in a few hours like a cryomagnet. It is also designed to be used in conjonction with aerodynamic levitation.