Patents by Inventor Joel N. Ullom

Joel N. Ullom has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6581387
    Abstract: A normal-insulator-superconductor (NIS) microrefrigerator in which a superconducting single crystal is both the substrate and the superconducting electrode of the NIS junction. The refrigerator consists of a large ultra-pure superconducting single crystal and a normal metal layer on top of the superconducting crystal, separated by a thin insulating layer. The superconducting crystal can be either cut from bulk material or grown as a thick epitaxial film. The large single superconducting crystal allows quasiparticles created in the superconducting crystal to easily diffuse away from the NIS junction through the lattice structure of the crystal to normal metal traps to prevent the quasiparticles from returning across the NIS junction. In comparison to thin film NIS refrigerators, the invention provides orders of magnitude larger cooling power than thin film microrefrigerators.
    Type: Grant
    Filed: February 12, 2002
    Date of Patent: June 24, 2003
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Joel N. Ullom