+ Visit NASA.gov + Contact NASA   + Home Collection > NASA  Author > Chui, Talso  Author > Penanen, Konstantin  NASA Center > Jet Propulsion Laboratory  Publication Year > 2001-2010 > 2008  Subject > P-R > Physics (general)  Availability Options > Order From CASI > CD-ROM, DVD, Print  Availability Options > Online > PDF  Item/Media Type > NASA Tech Brief  Item/Media Type > NASA Report > Technical Memorandum (TM)  Note: Start a new navigation search by selecting a link above     Previous Record | Next Record + Back to Results   + Printer Friendly Title: Thermally Driven Josephson Effect Author(s): Penanen, Konstantin; Chui, Talso Abstract: A concept is proposed of the thermally driven Josephson effect in superfluid helium. Heretofore, the Josephson effect in a superfluid has been recognized as an oscillatory flow that arises in response to a steady pressure difference between two superfluid reservoirs separated by an array of submicron-sized orifices, which act in unison as a single Josephson junction. Analogously, the thermally driven Josephson effect is an oscillatory flow that arises in response to a steady temperature difference. The thermally driven Josephson effect is partly a consequence of a quantum- mechanical effect known as the fountain effect, in which a temperature difference in a superfluid is accompanied by a pressure difference. The thermally driven Josephson effect may have significance for the development of a high-resolution gyroscope based on the Josephson effect in a superfluid: If the pressure-driven Josephson effect were used, then the fluid on the high-pressure side would become depleted, necessitating periodic interruption of operation to reverse the pressure difference. If the thermally driven Josephson effect were used, there would be no net flow and so the oscillatory flow could be maintained indefinitely by maintaining the required slightly different temperatures on both sides of the junction. NASA Center: Jet Propulsion Laboratory Publication Date: November 2008 Document Source: CASI Online Source: View Image File Order Document: Go to Tips On Ordering Document ID: 20080047229 Publication Information: NASA Tech Briefs, November 2008, 27, Number of Pages = 1 Report Number: NPO-40231 Price Code: A01 Keywords: JOSEPHSON EFFECT; OSCILLATIONS; TEMPERATURE GRADIENTS; QUANTUM MECHANICS; TEMPERATURE EFFECTS; LIQUID HELIUM; SUPERFLUIDITY; GYROSCOPES; JOSEPHSON JUNCTIONS; Accessibility: Unclassified; Copyright; Unlimited; Publicly available; Updated/Added to NTRS: 2008-12-22 + Back to Top + Sponsored by the NASA Scientific and Technical    Information Program + 2004 Vision for Space Exploration + Freedom of Information Act + NASA Web Privacy Policy and Important Notices + NASA Disclaimers, Copyright Notice,    and Terms and Conditions of Use NASA Official: Calvin Mackey Page Curator: NASA Center for AeroSpace Information (help@sti.nasa.gov) Last Updated: July 5, 2007