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

This experiment will measure the microstructure of Amorphous Solid Water (ASW), a porousmaterial 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 has shown thatthe ASW has very small-scale porosity, and hints at larger scale structure of the material; and our recentresults on ISIS SANS2D showed a good overlap with these data and gave us information about aggregation and collapse of pores.This experiments aims to reproduce these results at various temperatures to elucidate how the deposition temperature modifies the pores thermal evolution.