Budker Seminar: Darren R. Veit

US/Central
Meeting Room (Users Center)

Meeting Room

Users Center

Description
Hydrogen Loading and Cryogenic Scanning Tunneling Microscopy Imaging of Single Crystal Nb(100)



Niobium superconducting RF cavities uptake hydrogen during standard surface polishing techniques such as buffered chemical polishing. Absorbed hydrogen can precipitate as ordered niobium hydride phases during cooldown at cryogenic temperatures. Niobium hydrides are non-superconducting at 2K and cause cavity losses. In order to study nanoscale hydride precipitates I hydrogen load single crystal Nb(100) for scanning tunneling microscopy imaging. I report desorption profiles depicting hydrogen that has been loaded in a Nb(100) single crystal through gas-phase doping in UHV. I report scanning tunneling microscopy images depicting the Nb(100) surface at 25 K before and after hydrogen loading. My initial results show small clusters of precipitates on the niobium surface that are a result of the hydrogen loading of the niobium crystal. 
    • 17:00 17:20
      Refreshments 20m
    • 17:20 18:30
      Hydrogen Loading and Cryogenic Scanning Tunneling Microscopy Imaging of Single Crystal Nb(100) 1h 10m
      Niobium superconducting RF cavities uptake hydrogen during standard surface polishing techniques such as buffered chemical polishing. Absorbed hydrogen can precipitate as ordered niobium hydride phases during cooldown at cryogenic temperatures. Niobium hydrides are non-superconducting at 2K and cause cavity losses. In order to study nanoscale hydride precipitates I hydrogen load single crystal Nb(100) for scanning tunneling microscopy imaging. I report desorption profiles depicting hydrogen that has been loaded in a Nb(100) single crystal through gas-phase doping in UHV. I report scanning tunneling microscopy images depicting the Nb(100) surface at 25 K before and after hydrogen loading. My initial results show small clusters of precipitates on the niobium surface that are a result of the hydrogen loading of the niobium crystal.
      Speaker: Mr Darren Veit