Neutron beam measurements on grain growth in D2O ice: constraining grain growth rates in-situ

Love, Harriet

Grain growth kinetics in terms of the grain growth exponent are largely unconstrained, due to difficulties in measuring grain size in 2D. I present new in-situ neutron diffraction experiments using the KOWARI residual stress diffractometer at the Australian Nuclear Science and Technology Organisation (ANSTO). D2O ice rock was warmed, allowing us to observe and constrain grain size evolution throughout time. Error is still prevalent, and is heavily discussed in the following report. Slower grain growth rates in these experiments may be due to residual porosity, however more investigation needs to occur in regards to potential differences in the molecular kinetics of D2O and H2O. Parallel grain growth experiments were also performed at the Otago laboratory with the aim of comparing them to the neutron diffraction data. However, there is significant error associated with measuring a 3D object in 2D space. Neutron diffraction techniques have high potential to resolve grain growth evolution throughout time, among other microstructural processes.

81 pages A4

2016Love