Browsing by Subject "Heat pipe"
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Item A comparative study of entrainment in supersonic beams(2016-08) Burkhardt, Karl Austin; Raizen, Mark G.; Sitz, Greg OIn the field of atomic physics, there is a growing demand for large numbers of dense, trapped atoms. The traditional method of generating trapped atoms is through laser cooling, however the field has reached saturation in terms of cold atom flux and phase-space density and is fundamentally limited to atoms that can be addressed using a two-level transition accessible with available lasers. Because of this a new, more general technique of generating dense clouds of trapped atoms is necessary. This technique will surpass laser cooling with higher cold atom flux and phase-space density, as well as be applicable to particles which cannot be put into a two-level system. This thesis explores the first step necessary for the generation of a new method of cooling which will be more general than laser cooling and will produce a higher cold atom flux in denser phase-space. This method of cooling will rely on the sympathetic cooling of vaporized particles with a pulsed supersonic beam before slowing the entrained particles to rest using magnetic fields. Because the cooling in the entrainment step relies on sympathetic cooling, there is no two-level requirement and thus it is applicable to all paramagnetic species including both atoms and molecules. The experiments outlined in this thesis focus on utilizing different methods of entraining vaporized atoms into a supersonic beam as an alternative method of generating cold atoms. A comprehensive comparison of entrainment efficiency using these different entrainment techniques is included as well as a discussion regarding future applications of this new cooling process.Item Analytical and experimental investigation of capillary forces induced by nanopillars for thermal management applications(2010-05) Zhang, Conan; Hidrovo, Carlos H.This thesis presents an analytical and experimental investigation into the capillary wicking limitation of an array of pillars. Commercial and nanopillar wicks are examined experimentally to assess the effects of micro and nanoscale capillary forces. By exerting a progressively higher heat flux on the wick, a maximum achievable mass flow was observed at the capillary limit. Through the balance of capillary and viscous forces, an ab initio analytical model is also presented to support the experimental data. Comparison of the capillary limit predicted by the analytical model and actual limit observed in experimental results are presented for three baseline wicks and two nanowicks.