SRF2013 - List of Authors (Xiao, B. P.)

Paper

Title

Page

A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor

63

B. P. Xiao, C.E. Reece
JLab, Newport News, Virginia, USA
B. P. Xiao
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored in part by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
There is a need to understand the intrinsic limit of RF surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of Mattis-Bardeen theory of the RF surface impedance of BCS superconductors, based on the shifted density of states resulting from coherently moving Cooper pairs. Our theoretical prediction of the effective BCS RF surface resistance of niobium as a function of peak surface magnetic field amplitude agrees well with recently reported record low loss resonant cavity measurements from JLab and Fermi Lab with carefully prepared niobium material. The surprising reduction in resistance with increasing field is explained to be an intrinsic effect.

Slides MOIOC02 [3.122 MB]

MOP017

SRF for Low Energy RHIC Electron Cooling: Preliminary Considerations

126

S.A. Belomestnykh, I. Ben-Zvi, M. Blaskiewicz, A.V. Fedotov, D. Kayran, V. Litvinenko, Q. Wu, B. P. Xiao, W. Xu, A. Zaltsman
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko
Stony Brook University, Stony Brook, USA
Z.A. Conway, M.P. Kelly, S.V. Kutsaev, B. Mustapha, P.N. Ostroumov
ANL, Argonne, USA

Funding: Work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE
A search for the QCD Critical Point has renewed interest to electron cooling ion beams in RHIC at energies below 10 GeV/nucleon. The electron cooling will utilize bunched electron beams form an SRF linac at energies from 0.9 to 5 MeV. The SRF linac will consist of two quarter wave structures: a photoemission electron gun and a booster cavity. In this paper we present preliminary design consideration of this SRF linac.

TUP011

A Parametric Study of BCS RF Surface Impedance with Magnetic Field Using Xiao Code

444

C.E. Reece
JLab, Newport News, Virginia, USA
B. P. Xiao
JLAB, Newport News, Virginia, USA
B. P. Xiao
BNL, Upton, Long Island, New York, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
A recent new analysis of field-dependent BCS RF surface impedance based on moving Cooper pairs has been presented.* Using this analysis coded in Mathematica™, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the “best theoretical” performance available to potential applications with corresponding materials.
* Xiao B. P. et al, Physica C: Superconductivity, 490, 2013, pp. 26–31

TUP070

Characterization of Superconducting Samples With SIC System for Thin Film Developments: Status and Recent Results.

599

G.V. Eremeev, H.L. Phillips, A-M. Valente-Feliciano
JLAB, Newport News, Virginia, USA
C.E. Reece
JLab, Newport News, Virginia, USA
B. P. Xiao
BNL, Upton, Long Island, New York, USA

Funding: Work supported by DOE. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
Within any thin film development program directed towards SRF accelerating structures, there is a need for an RF characterization device that can provide information about RF properties of small samples. The current installation of the RF characterization device at Jefferson Lab is Surface Impedance Characterization (SIC) system. The data acquisition environment for the system has recently been improved to allow for automated quicker measurement, and the system has been routinely used for characterization of bulk Nb, films of Nb on Cu, MgB2, NbTiN, Nb3Sn films, etc. We present some of the recent results that illustrate present capabilities and limitations of the system.

THP041

Optimization of the Double Quarter Wave Crab Cavity Prototype for Testing at SPS

995

S. Verdú-Andrés, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi
Stony Brook University, Stony Brook, USA
R. Calaga
CERN, Geneva, Switzerland
Z. Li
SLAC, Menlo Park, California, USA

Funding: Research supported by EU FP7 HiLumi LHC – No. 284404, and by US DOE through Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 and the US LHC Accelerator Research Program (LARP).
The crab cavity program for LHC luminosity upgrade envisages the testing of at least one of the three competing crab cavities in the Super Proton Synchrotron (SPS) of CERN by 2016. This paper presents the design optimization of a Double Quarter Wave Crab Cavity (DQWCC) prototype suited for testing in SPS.

THP043

Design and Vertical Test of Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade

1002

B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, C. Cullen, L.R. Hammons, J. Skaritka, S. Verdú-Andrés, Q. Wu
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi
Stony Brook University, Stony Brook, USA

Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with LARP and the U.S. DOE, and supported by EU FP7 HiLumi LHC - Grant Agreement 284404.
A proof of principle Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. Vertical cryogenic test has been done in Brookhaven National Lab (BNL). We report the test results of this design.

THP044

Compact Higher Order Mode Filter for Crab Cavities in the Large Hadron Collider

1006

B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, S. Verdú-Andrés, Q. Wu
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi
Stony Brook University, Stony Brook, USA
R. Calaga
CERN, Geneva, Switzerland

Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with LARP and the U.S. DOE, and supported by EU FP7 HiLumi LHC - Grant Agreement 284404.
A double quarter wave crab cavity was designed for the Large Hadron Collider luminosity upgrade. Starting from the analytical calculation of simplified RLC circuit, a compact higher order mode filter is developed for this cavity. Finite element simulation results are presented. The design concept is generic and can easily be adapted to other cavities.

TUP011

A Parametric Study of BCS RF Surface Impedance with Magnetic Field Using Xiao Code

444

C.E. Reece
JLab, Newport News, Virginia, USA
B. P. Xiao
JLAB, Newport News, Virginia, USA
B. P. Xiao
BNL, Upton, Long Island, New York, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
A recent new analysis of field-dependent BCS RF surface impedance based on moving Cooper pairs has been presented.* Using this analysis coded in Mathematica™, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the “best theoretical” performance available to potential applications with corresponding materials.
* Xiao B. P. et al, Physica C: Superconductivity, 490, 2013, pp. 26–31

Paper	Title	Page
MOIOC02	A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor	63
	B. P. Xiao, C.E. Reece JLab, Newport News, Virginia, USA B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored in part by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. There is a need to understand the intrinsic limit of RF surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of Mattis-Bardeen theory of the RF surface impedance of BCS superconductors, based on the shifted density of states resulting from coherently moving Cooper pairs. Our theoretical prediction of the effective BCS RF surface resistance of niobium as a function of peak surface magnetic field amplitude agrees well with recently reported record low loss resonant cavity measurements from JLab and Fermi Lab with carefully prepared niobium material. The surprising reduction in resistance with increasing field is explained to be an intrinsic effect.
	Slides MOIOC02 [3.122 MB]

MOP017	SRF for Low Energy RHIC Electron Cooling: Preliminary Considerations	126
	S.A. Belomestnykh, I. Ben-Zvi, M. Blaskiewicz, A.V. Fedotov, D. Kayran, V. Litvinenko, Q. Wu, B. P. Xiao, W. Xu, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi, V. Litvinenko Stony Brook University, Stony Brook, USA Z.A. Conway, M.P. Kelly, S.V. Kutsaev, B. Mustapha, P.N. Ostroumov ANL, Argonne, USA
	Funding: Work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE A search for the QCD Critical Point has renewed interest to electron cooling ion beams in RHIC at energies below 10 GeV/nucleon. The electron cooling will utilize bunched electron beams form an SRF linac at energies from 0.9 to 5 MeV. The SRF linac will consist of two quarter wave structures: a photoemission electron gun and a booster cavity. In this paper we present preliminary design consideration of this SRF linac.

TUP011	A Parametric Study of BCS RF Surface Impedance with Magnetic Field Using Xiao Code	444
	C.E. Reece JLab, Newport News, Virginia, USA B. P. Xiao JLAB, Newport News, Virginia, USA B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. A recent new analysis of field-dependent BCS RF surface impedance based on moving Cooper pairs has been presented.* Using this analysis coded in Mathematica™, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the “best theoretical” performance available to potential applications with corresponding materials. * Xiao B. P. et al, Physica C: Superconductivity, 490, 2013, pp. 26–31

TUP070	Characterization of Superconducting Samples With SIC System for Thin Film Developments: Status and Recent Results.	599
	G.V. Eremeev, H.L. Phillips, A-M. Valente-Feliciano JLAB, Newport News, Virginia, USA C.E. Reece JLab, Newport News, Virginia, USA B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: Work supported by DOE. Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Within any thin film development program directed towards SRF accelerating structures, there is a need for an RF characterization device that can provide information about RF properties of small samples. The current installation of the RF characterization device at Jefferson Lab is Surface Impedance Characterization (SIC) system. The data acquisition environment for the system has recently been improved to allow for automated quicker measurement, and the system has been routinely used for characterization of bulk Nb, films of Nb on Cu, MgB2, NbTiN, Nb3Sn films, etc. We present some of the recent results that illustrate present capabilities and limitations of the system.

THP041	Optimization of the Double Quarter Wave Crab Cavity Prototype for Testing at SPS	995
	S. Verdú-Andrés, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, Q. Wu, B. P. Xiao BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi Stony Brook University, Stony Brook, USA R. Calaga CERN, Geneva, Switzerland Z. Li SLAC, Menlo Park, California, USA
	Funding: Research supported by EU FP7 HiLumi LHC – No. 284404, and by US DOE through Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 and the US LHC Accelerator Research Program (LARP). The crab cavity program for LHC luminosity upgrade envisages the testing of at least one of the three competing crab cavities in the Super Proton Synchrotron (SPS) of CERN by 2016. This paper presents the design optimization of a Double Quarter Wave Crab Cavity (DQWCC) prototype suited for testing in SPS.

THP043	Design and Vertical Test of Double Quarter Wave Crab Cavity for LHC Luminosity Upgrade	1002
	B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, R. Calaga, C. Cullen, L.R. Hammons, J. Skaritka, S. Verdú-Andrés, Q. Wu BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi Stony Brook University, Stony Brook, USA
	Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with LARP and the U.S. DOE, and supported by EU FP7 HiLumi LHC - Grant Agreement 284404. A proof of principle Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. Vertical cryogenic test has been done in Brookhaven National Lab (BNL). We report the test results of this design.

THP044	Compact Higher Order Mode Filter for Crab Cavities in the Large Hadron Collider	1006
	B. P. Xiao, S.A. Belomestnykh, I. Ben-Zvi, J. Skaritka, S. Verdú-Andrés, Q. Wu BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi Stony Brook University, Stony Brook, USA R. Calaga CERN, Geneva, Switzerland
	Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with LARP and the U.S. DOE, and supported by EU FP7 HiLumi LHC - Grant Agreement 284404. A double quarter wave crab cavity was designed for the Large Hadron Collider luminosity upgrade. Starting from the analytical calculation of simplified RLC circuit, a compact higher order mode filter is developed for this cavity. Finite element simulation results are presented. The design concept is generic and can easily be adapted to other cavities.

TUP011	A Parametric Study of BCS RF Surface Impedance with Magnetic Field Using Xiao Code	444
	C.E. Reece JLab, Newport News, Virginia, USA B. P. Xiao JLAB, Newport News, Virginia, USA B. P. Xiao BNL, Upton, Long Island, New York, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. A recent new analysis of field-dependent BCS RF surface impedance based on moving Cooper pairs has been presented.* Using this analysis coded in Mathematica™, survey calculations have been completed which examine the sensitivities of this surface impedance to variation of the BCS material parameters and temperature. The results present a refined description of the “best theoretical” performance available to potential applications with corresponding materials. * Xiao B. P. et al, Physica C: Superconductivity, 490, 2013, pp. 26–31