Passivated niobium cavities

Myneni, Ganapati Rao; Hjorvarsson, Bjorgvin; Ciovati, Gianluigi

Title: Passivated niobium cavities

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Abstract

A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.

Inventors:

Myneni, Ganapati Rao ^[1]; Hjorvarsson, Bjorgvin ^[2]; Ciovati, Gianluigi ^[3]

Yorktown, VA
Lagga Arby, SE
Newport News, VA

Issue Date:: 2006-12-19

Research Org.:: Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 982424

Patent Number(s):: 7151347

Application Number:: 11/168,198

Assignee:: Jefferson Science Associates LLC (Newport News, VA)

Patent Classifications (CPCs):: H - ELECTRICITY H05 - ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR H05H - PLASMA TECHNIQUE

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01P - WAVEGUIDES

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H - ELECTRICITY H05 - ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR H05H - PLASMA TECHNIQUE
H05H7/20 - with superconductive walls

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01P - WAVEGUIDES
H01P11/008 - {Manufacturing resonators}

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DOE Contract Number:: AC05-84ER40150

Resource Type:: Patent

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE

Citation Formats


                    Myneni, Ganapati Rao, Hjorvarsson, Bjorgvin, and Ciovati, Gianluigi. Passivated niobium cavities.  United States: N. p., 2006. 
        Web.

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                    Myneni, Ganapati Rao, Hjorvarsson, Bjorgvin, & Ciovati, Gianluigi. Passivated niobium cavities.  United States.

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                    Myneni, Ganapati Rao, Hjorvarsson, Bjorgvin, and Ciovati, Gianluigi. Tue .  
        "Passivated niobium cavities".  United States.  https://www.osti.gov/servlets/purl/982424.

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@article{osti_982424,

  title        = {Passivated niobium cavities},

  author       = {Myneni, Ganapati Rao and Hjorvarsson, Bjorgvin and Ciovati, Gianluigi},

  abstractNote = {A niobium cavity exhibiting high quality factors at high gradients is provided by treating a niobium cavity through a process comprising: 1) removing surface oxides by plasma etching or a similar process; 2) removing hydrogen or other gases absorbed in the bulk niobium by high temperature treatment of the cavity under ultra high vacuum to achieve hydrogen outgassing; and 3) assuring the long term chemical stability of the niobium cavity by applying a passivating layer of a superconducting material having a superconducting transition temperature higher than niobium thereby reducing losses from electron (cooper pair) scattering in the near surface region of the interior of the niobium cavity. According to a preferred embodiment, the passivating layer comprises niobium nitride (NbN) applied by reactive sputtering.},

  doi          = {},

  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {2006},

  month        = {12}

}

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