SRF2019 - List of Authors (Owen, P.D.)

Paper	Title	Page
TUP053	Optimal Thermal Gradient for Flux Expulsion in 600°C Heat-treated CEBAF 12 GeV Upgrade Cavities	550
	R.L. Geng, F. Marhauser, P.D. Owen JLab, Newport News, Virginia, USA
	We will present results on measurement of flux expulsion in CEBAF 12 GeV upgrade cavities and original CEBAF cavities and the search for optimal thermal gradient for reducing the trapped flux in cavities installed in CEBAF linacs. Preliminary measurements of one C100 cavities has shown that a nearly perfect flux expulsion can be achieved at an optimal thermal gradient - a surprising result contrary to the expectation of zero flux expulsion for 600°C heat treated niobium cavities. These results could lead to a cost-effective path for improving the quality factor of cavities installed in CEBAF and ultimately saving accelerator operation cost.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP053
About •	paper received ※ 24 June 2019 paper accepted ※ 29 June 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP094	Improvements to LCLS-II Cryomodule Transportation	684
	N.A. Huque, E. Daly, P.D. Owen JLab, Newport News, Virginia, USA B.D. Hartsell, J.P. Holzbauer Fermilab, Batavia, Illinois, USA
	The Linear Coherent Light Source (LCLS-II) is currently being constructed at the SLAC National Laboratory. A total of 35 cryomodules will be fabricated at Jefferson Lab (JLab) in Virginia and Fermi National Laboratory (FNAL) in Illinois and transported via road to SLAC. A shipping frame with an inner bed isolated by springs was designed to protect the CMs from shocks and vibrations during shipments. Successful road testing of the JLab prototype paved the way for production CM shipments. The initial production shipments lead to several catastrophic failures in beamline vacuum in the cryomodules. The failures were determined to be due to fatigue in Fundamental Power Coupler (FPC) bellows due to excessive motion during shipment. A series of instrumented CM shipping tests and component tests were undertaken to develop a solution. A modified spring layout was tested and implemented, which reduced shocks on the CMs. FPC coupler bellows restraints were tested on a shaker table and on a CM during shipping; they were able to reduce bellows motion by a factor of three. The updated shipping system is currently in use and has successfully delivered six cryomodules to SLAC from JLab and FNAL.
	Poster TUP094 [0.958 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP094
About •	paper received ※ 23 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Optimal Thermal Gradient for Flux Expulsion in 600°C Heat-treated CEBAF 12 GeV Upgrade Cavities

550

R.L. Geng, F. Marhauser, P.D. Owen
JLab, Newport News, Virginia, USA

We will present results on measurement of flux expulsion in CEBAF 12 GeV upgrade cavities and original CEBAF cavities and the search for optimal thermal gradient for reducing the trapped flux in cavities installed in CEBAF linacs. Preliminary measurements of one C100 cavities has shown that a nearly perfect flux expulsion can be achieved at an optimal thermal gradient - a surprising result contrary to the expectation of zero flux expulsion for 600°C heat treated niobium cavities. These results could lead to a cost-effective path for improving the quality factor of cavities installed in CEBAF and ultimately saving accelerator operation cost.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP053

About •

paper received ※ 24 June 2019 paper accepted ※ 29 June 2019 issue date ※ 14 August 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUP094

Improvements to LCLS-II Cryomodule Transportation

684

N.A. Huque, E. Daly, P.D. Owen
JLab, Newport News, Virginia, USA
B.D. Hartsell, J.P. Holzbauer
Fermilab, Batavia, Illinois, USA

The Linear Coherent Light Source (LCLS-II) is currently being constructed at the SLAC National Laboratory. A total of 35 cryomodules will be fabricated at Jefferson Lab (JLab) in Virginia and Fermi National Laboratory (FNAL) in Illinois and transported via road to SLAC. A shipping frame with an inner bed isolated by springs was designed to protect the CMs from shocks and vibrations during shipments. Successful road testing of the JLab prototype paved the way for production CM shipments. The initial production shipments lead to several catastrophic failures in beamline vacuum in the cryomodules. The failures were determined to be due to fatigue in Fundamental Power Coupler (FPC) bellows due to excessive motion during shipment. A series of instrumented CM shipping tests and component tests were undertaken to develop a solution. A modified spring layout was tested and implemented, which reduced shocks on the CMs. FPC coupler bellows restraints were tested on a shaker table and on a CM during shipping; they were able to reduce bellows motion by a factor of three. The updated shipping system is currently in use and has successfully delivered six cryomodules to SLAC from JLab and FNAL.

Poster TUP094 [0.958 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-SRF2019-TUP094

About •

paper received ※ 23 June 2019 paper accepted ※ 01 July 2019 issue date ※ 14 August 2019

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)