Method for in situ and in operando cavity loaded Q extraction in superconducting rf accelerators

Marhauser, Frank

doi:10.1103/PhysRevAccelBeams.24.032001

Title: Method for in situ and in operando cavity loaded $Q$ extraction in superconducting rf accelerators

Abstract

A novel method has been developed that allows extracting the loaded quality factor of particle accelerating radio-frequency cavities at any time during beam operation from acquired control system process parameters without the need of additional measurement equipment. Concurrently it assesses the attenuation in a cavities’ power transmission line for any rf generator to rf cavity mismatch condition, and thus can correct calibration inaccuracies of measured forward and reflected power levels. The mathematical formalism is described. It is specifically derived for cryogenically cooled superconducting cavities for which the loaded quality factor can be equated with the external quality factor of the input power coupler. The described method has been applied for 418 superconducting cavities in operation at the Continuous Electron Beam Accelerator Facility at the Thomas Jefferson National Accelerator Facility. The validation of the method as well as its beneficial use as a diagnostic tool is demonstrated for a finite number of examples utilizing process variables archived during a period in the past when the linac beam current was ramped up multiple times. The method is in the process of being implemented in the machines’ control system for an in situ and in operando evaluation of the power coupler’s external qualitymore » factor.« less

Authors:

Publication Date:: Fri Mar 19 00:00:00 EDT 2021

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

Sponsoring Org.:: USDOE Office of Science (SC), Nuclear Physics (NP)

OSTI Identifier:: 1771847

Alternate Identifier(s):: OSTI ID: 1771944

Report Number(s):: JLAB-ACC-20-3198; DOE/OR/23177-4976
Journal ID: ISSN 2469-9888; PRABCJ; 032001

Grant/Contract Number:: AC05-06OR23177

Resource Type:: Published Article

Journal Name:: Physical Review Accelerators and Beams

Additional Journal Information:: Journal Name: Physical Review Accelerators and Beams Journal Volume: 24 Journal Issue: 3; Journal ID: ISSN 2469-9888

Publisher:: American Physical Society

Country of Publication:: United States

Language:: English

Subject:: 43 PARTICLE ACCELERATORS; Radio frequency calculations; radio frequency techniques; superconducting RF

Citation Formats


                    Marhauser, Frank. Method for in situ and in operando cavity loaded Q extraction in superconducting rf accelerators.  United States: N. p., 2021. 
Web.  doi:10.1103/PhysRevAccelBeams.24.032001.

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                    Marhauser, Frank. Method for in situ and in operando cavity loaded Q extraction in superconducting rf accelerators.  United States.  https://doi.org/10.1103/PhysRevAccelBeams.24.032001

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                    Marhauser, Frank. Fri .  
"Method for in situ and in operando cavity loaded Q extraction in superconducting rf accelerators".  United States.  https://doi.org/10.1103/PhysRevAccelBeams.24.032001.

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@article{osti_1771847,

  title        = {Method for in situ and in operando cavity loaded Q extraction in superconducting rf accelerators},

  author       = {Marhauser, Frank},

  abstractNote = {A novel method has been developed that allows extracting the loaded quality factor of particle accelerating radio-frequency cavities at any time during beam operation from acquired control system process parameters without the need of additional measurement equipment. Concurrently it assesses the attenuation in a cavities’ power transmission line for any rf generator to rf cavity mismatch condition, and thus can correct calibration inaccuracies of measured forward and reflected power levels. The mathematical formalism is described. It is specifically derived for cryogenically cooled superconducting cavities for which the loaded quality factor can be equated with the external quality factor of the input power coupler. The described method has been applied for 418 superconducting cavities in operation at the Continuous Electron Beam Accelerator Facility at the Thomas Jefferson National Accelerator Facility. The validation of the method as well as its beneficial use as a diagnostic tool is demonstrated for a finite number of examples utilizing process variables archived during a period in the past when the linac beam current was ramped up multiple times. The method is in the process of being implemented in the machines’ control system for an in situ and in operando evaluation of the power coupler’s external quality factor.},

  doi          = {10.1103/PhysRevAccelBeams.24.032001},

  journal      = {Physical Review Accelerators and Beams},

  number       = 3,

  volume       = 24,

  place        = {United States},

  year         = {Fri Mar 19 00:00:00 EDT 2021},

  month        = {Fri Mar 19 00:00:00 EDT 2021}

}

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Works referenced in this record:

Theory of Superconductivity
journal, December 1957

Bardeen, J.; Cooper, L. N.; Schrieffer, J. R.
Physical Review, Vol. 108, Issue 5
DOI: 10.1103/PhysRev.108.1175

Theory of the Anomalous Skin Effect in Normal and Superconducting Metals
journal, July 1958

Mattis, D. C.; Bardeen, J.
Physical Review, Vol. 111, Issue 2
DOI: 10.1103/PhysRev.111.412

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Similar Records

Title: Method for in situ and in operando cavity loaded Q extraction in superconducting rf accelerators

Abstract

Citation Formats

Theory of Superconductivity journal, December 1957

Theory of the Anomalous Skin Effect in Normal and Superconducting Metals journal, July 1958

Title: Method for in situ and in operando cavity loaded $Q$ extraction in superconducting rf accelerators

Theory of Superconductivity
journal, December 1957

Theory of the Anomalous Skin Effect in Normal and Superconducting Metals
journal, July 1958