Type of Thesis
The evolution of many interplanetary icy surfaces, which are prevalent throughout the solar system, is highly dependent on impact phenomena associated with frequent micrometeoroid (dust) bombardment. A quantifiable experimental investigation of these phenomena is incomplete, however, especially at impact energies similar to those encountered in space. Further efforts are necessary to understand the critical complex chemistry and surface weathering effects that result from hypervelocity dust impacts and to calibrate instruments for future space missions. This work describes the development of a novel cryogenic system that will facilitate the future study of hypervelocity dust impacts into ice and icy regolith. The experiment, located at the Institute for Modeling Plasmas, Atmospheres, and Cosmic Dust (IMPACT) of NASA's Solar System Exploration Research Virtual Institute (SSERVI), consists of a cryogenically-controlled target that is equipped with sensitive diagnostic tools and is designed to take full advantage of the existing dust-acceleration technologies at IMPACT. The target is cooled by liquid nitrogen and can hold layers of vapor-deposited H$_2$O, CH$_3$OH, or NH$_3$ ice, pre-frozen ice and icy regolith mixtures containing nanophase iron. The temperature of the ice can be varied between 96\,K and 150\,K via an internal feedback loop. Importantly, the ion plumes that are created during dust impacts onto these targets can be accelerated through a time-of-flight mass spectrometer, where their composition can be measured even in trace amounts. This work presents comprehensive design details of the IMPACT ice chamber and discusses key results from initial impacts into thick, vapor-deposited water ice.
Nelson, Andrew, "The development of a cryogenic chamber to study hypervelocity dust bombardment of ice and icy regolith" (2016). Undergraduate Honors Theses. 1230.