Linac4 Drift Tube Linac LIU Day 2014

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Linac4 Drift Tube LinacLIU Day 2014

Suitbert Ramberger, CERN, BE-RF-LRF

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Linac4 DTL – RF Design

● Introduction

– Design Parameters & Constraints

– Production Design

– Mechanical Concept

● Manufacturing and Assembly

– Manufacturing in Industry and at CERN

– Quality Issues

– Current Status

● Results of Tank1

– Quadrupole Positioning

– Field flatness

● Conclusions

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Linac4 Drift Tube Linac

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Linac4 DTL Design

DTL design parameters:● DTL from 3 – 50 MeV with 3 cavities and 1 LEP and 2 new klystrons● Klystron output power at cavity port 1 MW (Tank1) and 2 MW (Tank2&3)● Accelerating field at ~3.2 MV/m● Peak electric field of 1.6 Kilpatrick lowered to 1.2 Kilp. over the first cells● PMQs in vacuum● Self supporting steel cylinders of 50 mm thickness● Maximum segment length of 2 m

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Linac4 DTL Design

Parameter \Cavity

1 2 3

Cells per cavity 39 42 30

Accelerating field 3.1 MV/m 3.3 MV/m 3.3 MV/m

Maximum surface field 1.5 Kilp. 1.4 Kilp. 1.45 Kilp.

Synchronous phase -35 to -24 deg -24 deg -24 deg

RF peak power per cavity 1.00 MW 2.03 MW 1.98 MW

Quadrupole length 45 mm 80 mm 80 mm

Flat Size 11 mm 7 mm 5 mm

Number of sections 2 4 4

Length per cavity 3.8958 m 7.3406 m 7.2508 m

Beam output power 11.88 MeV 31.45 MeV 50.14 MeV

Production design:● RF design compatible with mechanical realization

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Linac4 DTL– Mechanical Design

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Linac4 DTL Mechanical Design

Linac4 Drift Tube Linac Mechanical Design:Make it as straightforward as possible:● Mechanical Design without position adjustment of Drift Tubes● Single Helicoflex gaskets for vacuum and RF sealing● Coaxial water cooling in Drift Tubes● No wires in Drift Tubes: PMQs, no instrumentation, thermal probes at top● Rigid steel support structure, w/o welds (almost), soft Aluminium girders

Consequence:● Precision Machining required, and tight Quality Control

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CERN Drift Tube Positioning

“Adjust and Assemble”

Horizontal andvertical positioning

Vacuum seal

Cooling water in

Cooling water out

Belleville washers

Pre-stress cylinder

Leak test seal

Thermo-probe andLeak test channel

Base plate

Bushing

Screw

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Linac4 DTL Manufacturing

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Linac4 DTL Manufacturing

Linac4 Drift Tube Linac Manufacturing:● Girder manufacturing at CADINOX, Veenstra Glazenborg & CERN● Retendering to Mancisidor and GoiAlde, Spain → Completed June 2013 ● Drift tube component machining, DMP, Spain → Completed January 2013● Drift tube assembly, CERN → Completed November 2013● Tank manufacturing at CADINOX, Spain → Completed February 2014● Tank plating, CERN → 5 Segments Completed, 1 Ongoing, 4 Waiting● Tank assembly, CERN → Tank1 Completed, Tank3 Ongoing

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Tank Manufacturing

Tank manufacturing:● Order started November 2010● Manufacturing of 1 pre-series segment T1S1 completed October 2011

– Pre-series segment fully in specification● Machining error on deep drilled cooling channels found March 2012

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Cooling channel repair

Crash program:● Definition of analysis procedure by ultrasound● Analysis of all segments: 9 segments out of tolerances, 2 to be repaired● Definition of repair with inserts● Successful test on sample pieces at manufacturer● Ordering of dedicated machining tool● Machining of defined channel opening● Failed repair on tank segments at manufacturer● Remachining of defined channel opening● Successful repair at CERN – T3S3 sent back, T1S2 at CERN (May 2013)

Other issues:

● Other leaks (water to air) plugged● Re-machining of segments out of tolerances● Non-connected cooling channel

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Linac4 DTL Tank Status

Tank status:● T1S1 & T1S2 assembled and joined as Tank1 – in completion● T3S1, T3S2 & T3S4 assembled● T3S3 under copper plating● T2S1-S4 at CERN

Current tasks:● Verifications and completion of Tank1● Copper plating of remaining segments in competition with LS1● Assembly of segments of Tank3

● Manufacturing of wave-guide couplers & movable tuners

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Linac4 DTL Tank1 Results

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Linac4 DTL Tank1 Results

Quadrupole positioning: Horizontal / Longitudinal / Vertical

J.-F. Fuchs

T1S1_

DT101

T1S1_

DT103

T1S1_

DT105

T1S1_

DT107

T1S1_

DT109

T1S1_

DT111

T1S1_

DT113

T1S1_

DT115

T1S1_

DT117

T1S1_

DT119

T1S1_

DT121

T1S2_

DT123

T1S2_

DT125

T1S2_

DT127

T1S2_

DT129

T1S2_

DT131

T1S2_

DT133

T1S2_

DT135

T1S2_

DT137

-0.100

-0.080

-0.060

-0.040

-0.020

0.000

0.020

0.040

0.060

0.080

0.100X avg horiz. mm

Y avg long. mm

Z avg vert mm

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Linac4 DTL Tank1 Results

Tuning: E0 variation within +/- 1.35%

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 390.985

0.99

0.995

1

1.005

1.01

1.015

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Linac4 Drift Tube Linac – Conclusions

Conclusions:

● The Linac4 Drift Tube Linac is a prototype

● Manufacturing requires tight quality control

● Considerable quality issues have been overcome

● Almost all major components have been completed

● Last manufacturing stages are in competition with LS1

● The Drift Tube Linac is a puzzle of a thousand pieces

● Final assembly is on its way