Development of Operations Manual and Restoration of Cryogenic System for Magnetic Levitation

The simulation and study of fluid properties and dynamics in a microgravity environment on the Earth’s surface is of great interest due to the high costs associated with conducting research in space. Cryogenic fluids like liquid helium, hydrogen, and oxygen have numerous applications in space travel and research. An understanding of their sloshing motion and general dynamics in microgravity is extremely valuable for maintaining proper orientation of spacecraft and proper cooling. The ability to study fluids with no surfaces in contact with their container allows greater flexibility in the study such fluid dynamics, and enables deeper research into quantum turbulence to be conducted. Simulating this microgravity environment on the earth is highly desirable, and may be achieved by using drop towers, acoustic levitation, laser levitation, zero-g planes, and superconducting magnets. The stable magnetic levitation of diamagnetic fluids against the pull of gravity on the earth’s surface may be obtained by generating a strong magnetic field and specific magnetic field gradient. Stability of a levitated liquid drop requires a potential minimum to hold the drop along a central axis, with a field magnitude increasing with increasing radial displacement. The NHMFL cryogenics lab obtained a unique cryostat containing such a magnet, which was used for hydrogen and helium levitation, but which was in disrepair. This cryogenic facility arrived with dozens of leaks and no documentation explaining its structure, functions, or the procedures necessary to use it experimentally. The purpose of this thesis work has been to develop a complete understanding of this cryostat’s structures and functions, as well as the refinement of procedures to properly cool it down and safely operate its magnet. A user manual has been produced to fully document the experimental setup and all necessary procedures. Because this cryostat was received in such bad condition, much time was also committed to the identification of all its mechanical failures, vacuum and gas leaks, and their full repair. Additionally, all supporting pumping systems and gas handling systems were designed, constructed, and documented to facilitate proper and safe operation. Documenting and developing this cryogenic system required extensive designs for external controls and modifications to the system as a whole.