2011 Particle Accelerator Conference - List of Authors (Macha, K.)

Paper

Title

Page

Summary Report for the C50 Cryomodule Project

1044

M.A. Drury, G.K. Davis, J.F. Fischer, C. Grenoble, J. Hogan, L.K. King, K. Macha, J.D. Mammosser, C.E. Reece, A.V. Reilly, J. Saunders, H. Wang
JLAB, Newport News, Virginia, USA
E. Daly, J.P. Preble
ITER Organization, St. Paul lez Durance, France

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract DE-AC05-06OR23177.
The Thomas Jefferson National Accelerator Facility has recently completed the C50 cryomodule refurbishment project. The goal of this project was to enable robust 6 GeV, 5 pass operation of the Continuous Electron Beam Accelerator Facility (CEBAF). The scope of the project included removal, refurbishment and reinstallation of ten CEBAF cryomodules at a rate of three per year. The refurbishment process included reprocessing of SRF cavities to eliminate field emission and to increase the nominal gradient from the original 5 MV/m to 12.5 MV/m. New “dogleg“ couplers were installed between the cavity and helium vessel flanges to intercept secondary electrons that produce arcing in the fundamental Power Coupler (FPC). Other changes included new ceramic RF windows for the air to vacuum interface of the FPC and improvements to the mechanical tuner. Damaged or worn components were replaced as well. All ten of the refurbished cryomodules are now installed in CEBAF and are currently operational. This paper will summarize the performance of the cryomodules. This paper will also look at problems that must be addressed by future refurbishment projects.
The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

WEOCS7

Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source

1472

H. Wang, G. Cheng, G. Ciovati, W.A. Clemens, J. Henry, P. Kneisel, P. Kushnick, K. Macha, J.D. Mammosser, R.A. Rimmer, G. Slack, L. Turlington
JLAB, Newport News, Virginia, USA
R. Nassiri, G.J. Waldschmidt, G. Wu
ANL, Argonne, USA

Funding: Work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354.
Two single-cell, superconducting, squashed elliptical crab cavities with waveguides to damp Higher Order Modes (HOM) and Lower Order Mode (LOM) have been designed and prototyped for the Short Pulse X-ray (SPX) project at the Advanced Photon Source (APS). The Baseline cavity with LOM damper on the beam pipe has been vertically tested and exceeded its performance specification with over 0.5MV deflecting voltage. The Alternate cavity design which uses an “on-cell” waveguide damper is preferred due to its larger LOM impedance safety margin. Its prototype cavity has been fabricated by a Computer Numerical Controlled (CNC) machine and is subject to further testing. The conceptual design, layout and analysis for various cryomodule components are presented.

Slides WEOCS7 [7.008 MB]

Paper	Title	Page
TUP108	Summary Report for the C50 Cryomodule Project	1044
	M.A. Drury, G.K. Davis, J.F. Fischer, C. Grenoble, J. Hogan, L.K. King, K. Macha, J.D. Mammosser, C.E. Reece, A.V. Reilly, J. Saunders, H. Wang JLAB, Newport News, Virginia, USA E. Daly, J.P. Preble ITER Organization, St. Paul lez Durance, France
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract DE-AC05-06OR23177. The Thomas Jefferson National Accelerator Facility has recently completed the C50 cryomodule refurbishment project. The goal of this project was to enable robust 6 GeV, 5 pass operation of the Continuous Electron Beam Accelerator Facility (CEBAF). The scope of the project included removal, refurbishment and reinstallation of ten CEBAF cryomodules at a rate of three per year. The refurbishment process included reprocessing of SRF cavities to eliminate field emission and to increase the nominal gradient from the original 5 MV/m to 12.5 MV/m. New “dogleg“ couplers were installed between the cavity and helium vessel flanges to intercept secondary electrons that produce arcing in the fundamental Power Coupler (FPC). Other changes included new ceramic RF windows for the air to vacuum interface of the FPC and improvements to the mechanical tuner. Damaged or worn components were replaced as well. All ten of the refurbished cryomodules are now installed in CEBAF and are currently operational. This paper will summarize the performance of the cryomodules. This paper will also look at problems that must be addressed by future refurbishment projects. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

WEOCS7	Crab Cavity and Cryomodule Prototype Development for the Advanced Photon Source	1472
	H. Wang, G. Cheng, G. Ciovati, W.A. Clemens, J. Henry, P. Kneisel, P. Kushnick, K. Macha, J.D. Mammosser, R.A. Rimmer, G. Slack, L. Turlington JLAB, Newport News, Virginia, USA R. Nassiri, G.J. Waldschmidt, G. Wu ANL, Argonne, USA
	Funding: Work is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11354. Two single-cell, superconducting, squashed elliptical crab cavities with waveguides to damp Higher Order Modes (HOM) and Lower Order Mode (LOM) have been designed and prototyped for the Short Pulse X-ray (SPX) project at the Advanced Photon Source (APS). The Baseline cavity with LOM damper on the beam pipe has been vertically tested and exceeded its performance specification with over 0.5MV deflecting voltage. The Alternate cavity design which uses an “on-cell” waveguide damper is preferred due to its larger LOM impedance safety margin. Its prototype cavity has been fabricated by a Computer Numerical Controlled (CNC) machine and is subject to further testing. The conceptual design, layout and analysis for various cryomodule components are presented.
	Slides WEOCS7 [7.008 MB]