Evolution of porosity and structure of Amorphous Solid Water (ASW)

This experiment will measure the microstructure of Amorphous Solid Water (ASW), a porous material that can be formed by vapour-depositing water onto a cold plate, an excellent analogue ofthe ice found in star- and planet-forming regions of our galaxy. The thermal and temporal evolutionof this metastable condensed-matter material has major implications in the physical and chemicalrole ices play in astrophysical environments. Our previous results on ISIS NIMROD and SANS2D has shown that the ASW has very small-scale porosity, and hints at larger scale structure of the material and gave us information about aggregation and collapse of pores.This proposal aims to add 2 days to our previously accepted SANS2D proposal and reproduce these results with more deposition temperatures.