Gubrud, Mark AvrumThis dissertation reports on work toward the realization of a state-of-the-art scanning tunneling microscopy and spectroscopy facility operating at milliKelvin temperatures in a dilution refrigerator. Difficulties that have been experienced in prior efforts in this area are identified. Relevant issues in heat transport and in the thermalization and electrical filtering of wiring are examined, and results are applied to the design of the system. The design, installation and characterization of the pumps, plumbing and mechanical vibration isolation, and the design and installation of wiring and fabrication and characterization of electrical filters are described.Scanning Tunneling Microscopy at milliKelvin Temperatures: Design and ConstructionDissertationLow Temperature PhysicsNanoscienceNanotechnologymillikelvin stmmillikelvin technologynanotechnologyscanning tunneling micrsoscopy