NIMA Langmuir troughs on CRISP

There are two Nima Langmuir troughs available for use on CRISP and SURF. Both have double moveable barriers allowing the measurement of reflectivity curves in-situ over a very wide area enclosed by the barriers. Both troughs are computer controlled with a user friendly interface allowing flexibility of use. A majority of experiments will need to be carried out holding a fixed pressure over the length of the reflectivity measurement and this can easily be achieved as well as measuring more normal pressure-area curves. Full details of the use of the troughs can be found in the very helpful Nima handbook. The large Nima trough has moveable fixed barriers which allow the volume of subphase to be varied. The troughs both have perspex lids which incorporate neutron transparent quartz windows. This arrangement allows easy alignment of the liquid but prevents a majority of the airborne dust contaminants. This is not however a sealed unit and is therefore not vapour pressure tight. The troughs both have the possibility to link to a recirculating heater/cooling bath which has a maximum temperature range of -50 - 200 C. However, temperatures above 100 C are not recommended for the PTFE.

Care must be taken to ensure that the troughs are set up correctly and it is advised that users contact Robert Dalgliesh/Tim Charlton before using the equipment. Calibration of the area enclosed by the barriers will be done before users will have access to the troughs although calibration of the pressure head will be the responsibility of the individual users. Again contact Robert Dalgliesh/Tim Charlton if there are any problems.


A summary of the key features of the Nima troughs follows:

Small Nima Trough 
Internal dimensions200 ´ mm
Average area coverage90 - 540 cm2
Typical subphase volume300 cm3
Temperature range-50 - 100 C
Large Nima Trough 
Internal dimensions200 ´ mm
Average area coverage90 - 1080 cm2
Typical subphase volumeup to 1500 cm3
Temperature range-50 - 100 C
Name Troughs
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