Cloud Chamber
The new ice cloud chamber facility consists of three large cold rooms arranged vertically above each other on three floors of the building. These are joined by a 1m diameter 10m tall fall tube in which ice cloud properties and in particular crystal growth can be studied over much longer time scales than was possible using smaller chambers. Temperatures in the cold rooms can be controlled to -50C, with each of the three chambers able to be controlled separately. At each level there is laboratory space outside the cold room which can be used to house instrumentation to measure the conditions within the fall tube and access ports are provided at each level to facilitate connection of such instruments. At the base of the fall tube there is additional space within the cold room to allow a number of cloud microphysics probes to be mounted directly beneath the tube to maximise sampling efficiency. The external laboratory areas a linked by a dedicated staircase allowing access to all levels of the fall tube. In addition to using the entire fall tube, it is also possible to close off sections of the tube if smaller scale experiments are required. The fall tube itself can also be evacuated down to pressures of 50mbar allowing Upper Tropospheric and Lower Stratospheric conditions to be simulated. These facilities allow the study of ice, water and mixed phase cloud microphysical processes under carefully controlled conditions.
Over the years a considerable volume of work has been done by Dr. Clive Saunders and others on ice particle nucleation, riming, charge transfer, and interaction of radiation with ice particles, using older facilities at the Centre's old home in the Sackville Street Building (formerly UMIST Main Building). These new facilities will allow this work to continue and be expanded into new areas. Additionally, these new facilities will be used for instrument testing and calibration.