This Langmuir trough 09LTQZ70, optimised for the horizontal reflectometer FIGARO, is based on a Microtrough G1 by Kibron. The sample temperature is monitored with compact contactless pyrometers and controlled with a thermostatic bath. To ensure relatively rapid temperature changes while ensuring a perfect flatness, the troughs are made from hard aluminium coated with PTFE to enable easy cleaning without any contaminating glues or coatings.
It is possible to circulate a gas at a controlled flow-rate. The chamber is closed with a lid featuring an inclined window allowing the exact position of the liqud interface relative to the neutron beam to be measured. The lid is heated to prevent condensation and Sapphire windows, also heated, close the chamber and prevent spurious neutron scattering in the dectector. B4C plates are also implemented to reduce neutron background.
Barriers are controlled manually from the touch panel of the Programmable Logic Controller or remotely with NOMAD through the Kibron electronics. Their calibration is manual or semi-automatic and must be performed from the touch panel before closing the casemate. During neutron data acquisition, two modes of operation are proposed: area controlled and pressure controlled. In the pressure controlled mode, the movements of the barriers are determined by the Kibron electronics to maintain the desired pressure (static or dynamic).