Status and Progress

Andrew Burrill on behalf of the team

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Outline

• Overview of LCLS-II• Schedule • Cryomodule performance• Installation progress and challenges• Installation status• Looking forward to HE• Lessons learned

This talk will summarize the current status of the LCLS-II x-ray free electron laser installation progress and the upcoming commissioning plans. The overall state of the machine will be reviewed and a summary of the cryomodule performance in the testing facilities will be provided. In addition some of the key lessons learned from installation and integration will be discussed.

Slide 3

LCLS-IINew Injector andNew Superconducting Linac

Existing Bypass Line

New Transport Line

Two New UndulatorsAnd X-Ray Transport

Reconfigure Near Experiment Hall

New Cryoplant

Remove SLACLinac fromSectors 0-10

SRF'21 LCLS-II Status and Progress

Project Collaboration: SLAC couldn’t do this without…

SRF'21 LCLS-II Status and Progress 4

LCLS-II Project Timeline - 15 Months to First Light

RECENT PROGRESS

• Undulators installed and performance demonstrated with Cu linac

• Cryoplant #1 4.5K Cold box commissioning underway

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Cryoplant 1 Installation Complete

All Cryomodulesconnected

37 of 37 CryomodulesInstalled Today

Linac Cool Down/Commissioning

First Light

Undulator Installation Complete

All Undulators Installed

Today95% Complete

Cryoplant 1 Commissioning Complete

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The Linac – SRF Deliverables

• Receipt of 41 cryomodules at SLAC (38 – 1.3 GHz, 3 – 3.9 GHz)• Installation of 37 cryomodules (35 – 1.3 GHz, 3 – 3.9 GHz)• Installation of 37 beamline absorbers and 5 beamline bellows• Completion of 5 insulating vacuum sections• Termination of 40,000+ cables (linac and undulator halls)

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Cavity Summary – Demonstration of Industrial N2 Doping

• 373 – 1.3 GHz cavities ordered • 37 sent back to vendor

for rework• 304 installed in 38

production CMs• 26 – 3.9 GHz cavities

ordered• 2 sent back to vendor for

rework• 24 installed in 3

production CMs

1.3 GHz Cavity Parameter Value

Cavities Tested 410*

% Requiring Reprocessing 32%

% With FE In 1st Test 24%

% Not Solved by 1 Re-Rinse 2.9%

% Requiring EP to Clean FE 0.2%

% With Cold Leaks 2.9%

*Includes cavities that were reworkedOverall, cavity production reached similar re-processing rates to XFEL, but considerable

oversight was required*see D. Gonnella 2019 TTC talk for more details

All testing performed at Jefferson Lab and Fermilab Courtesy of Dan Gonnella

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Overall Cryomodule Performance – Individual Tests

Successful demonstration of the first large scale nitrogen doped SRF cavity production by Industry

Courtesy of Dan Gonnella

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Installation by the numbers

• 41 CMs delivered to SLAC from JLaband FNAL over a period of 2 years

• CM installation took place over 22 months

• CM interconnect welding

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Cryomodule Installation and Challenges

• 504 weld joints completed – 168 m of welding• 1 interconnect had to be repaired due to failure of 300

mm bellows – vendor defect• 42 particle free interconnections made

• Beamline height is a challenge

• 288 Solid State Amplifiers Installed (8 outstanding)• 74 LLRF Racks installed• LLRF -> HPRF integration testing underway

involves using the LLRF and SSAs to power warm CM cavities up to 400 Watts CW

• Waveguide non-ionizing radiation surveys are performed to ensure the waveguide is RF leak tight

• Power measurements are made at the directional couplers near the cryomodule for comparison to LLRF values

• SSAs are briefly (<200 µs) chirped to 4 kW and the SSA health is characterized

RF Installation and Checkout

Courtesy of Andy Benwell 11

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Take-aways

1. Industrial partners can adapt to meet our needs • N2 doping of SRF cavities

2. More time taken with vendors on the front end is critical3. Partnerships for big science are win win4. We (The SRF community) need to invest in training the

next generation of Scientist, Engineers and Technicians

Thanks to the dedication and hard work of a huge group of people LCLS-II is nearly ready for RF commissioning

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The End