High Resolution Thermal Expansion Measurements of Ice
This project is concerned with high-resolution measurements of the thermal expansion of single-crystalline ice at atmospheric pressure. The measurements will provide up to 10,000 times higher relative resolution than previous measurements, yielding new information about the anisotropy of the thermal expansion and the first structural investigation of a poorly understood phase transition at 115 K. Improved knowledge of ice's thermal expansion will impact cold-region engineering, climate modeling, the study of Earth's polar regions, astrophysics, and our basic understanding of the motion of hydrogen atoms in ice and their role in determining its physical properties. New temperature sensor technology resulting from this project will increase the relative resolution of temperature measurements by a factor of 100; this will improve determination of the thermal expansion coefficient, but may have other applications. A compact thermal expansion cell will be constructed of single-crystalline sapphire to facilitate measurements in the range 0.35 K to 20 K. Undergraduates will be responsible for a large portion of this project. They will fabricate experimental equipment, grow and orient single crystals, test and calibrate highly sensitive devices and learn fundamental physics associated with solids.