global design effort 1 s0 status high-gradient cavities lutz lilje desy supplement by h. hayano...

Global Design Effort 1

S0 Status High-Gradient cavities

Lutz Lilje

DESY

supplement by H. Hayano

04Sep2008 EC meeting@KEK

S0 Status Lutz Lilje DESY


Where are we?

• America and Asia– New vendors and new preparation setups

• Europe– Previous production cycle– Current production cycle– Preliminary data

Americas Summary (all tests)

0

5

10

15

20

25

30

35

40

45A

5

A6

A7

A8

A9

A11

A12

A15

AE

S1

AE

S2

AE

S3

AE

S4

ICH

IRO

5

9-cell cavity

max

gra

die

nt

[MV

/m]

0

5

10

15

20

25

30

35

40

45

1

JLabCornellFNALANL/JLabJLab/KEK

Reference;R. L. Geng et al., Proc. SRF2007, Beijing, WEP28 (2007).R. L. Geng et al., Proc. LINAC08, Victoria, Canada, in preparation.C. M. Ginsburg (FNAL), private communication.W. J. Ashmanskas and H. S. Padamsee, Proc. SRF2007, Beijing, WEP39 (2007).

4

Americas Summary (best test)

0

5

10

15

20

25

30

35

40

45A

5

A6

A7

A8

A9

A11

A12

A15

AE

S1

AE

S2

AE

S3

AE

S4

ICH

IRO

5

9-cell cavity

max

gra

die

nt

[MV

/m]

0

5

10

15

20

25

30

35

40

45

1 2 3 4 5 6 7 8 9 10

JLabCornellFNALJLab/KEK

KEK 9 cell cavity statusTESLA shape LL shape

BL#1 in module 20.8MV/m,Q=1.8x1010

MHI I9#1(LL#0) no coupler 29.3MV/m,Q=1.0x1010

Kuroki


MHI I9#2(LL#1) module tested 19.0MV/m,Q=0.4x1010

Kuroki


MHI I9#3(LL#2) 12.4MV/m,Q=1.2x1010

Kuroki


MHI I9#4(LL#3) for tuner test --- Kuroki

BL#5 under EP process

--- MHI I9#5 no coupler,KEK, JLab tested

22.0MV/m,Q=2.0x1010

(at KEK)

35.0MV/m,Q=0.8x1010

(at JLab)Kuroki

BL#6 under EP process

--- MHI I9#6(PAL) no coupler,now in PAL --- Korea

BL#7 under contract

--- I9#7new Ichiro

14.0MV/m,Q=0.7x1010

Kuroki

BL#8 under contract

--- I9#8new Ichiro

--- Kuroki

BL#9 under contract

--- I9#9new Ichiro

under plan ---



KEK Data: TESLA-Type

KEK TESLA-shape cavities

LL #5 S0 Studies at JLabUltrasonic Cleaning with degreaser much effective

to reduce Field Emission



DESY 4th: Field Emission Analysis

0123456

no.

of

cavi

ties EP w/o ethanol: Eonset

EP w/o ethanol: Emax

0123456

no.

of

cavi

ties EP with ethanol: E_onset

EP with ethanol: Emax

0123456

<16 16-18 18-20 20-22 22-24 24-26 26-28 28-30 30-32 32-34 34-36 36-38 38-40 40-42Gradient [MV/m]

no.

of

cavi

ties BCP ("EP+"): E_onset

BCP ("EP+"): Emax




0123456

no.

of

cavi



0123456

no.

of

cavi



0123456

<16 16-18 18-20 20-22 22-24 24-26 26-28 28-30 30-32 32-34 34-36 36-38 38-40 40-42Gradient [MV/m]

no.

of

cavi


BCP ("EP+"): EmaxOptical Inspection done

Z110

Z111

11

TESLA cavity Z110: #8 cell equator

Quench location

#8 equator

250 ~ 300 deg

1mm

#8 equator, t=288 ~ 299 deg

10mm

t=292 deg

t=297 deg

T-map data in test 2, 14.2 MV/m

group of beads(?) with 10mm wide were observed.Similar beads group were also observed in several places. see following slides.

12

TESLA cavity Z111: #6 cell equator

T-map data in test 2, 16.0 MV/m

Quench location

#6 equator

175 ~ 225 deg

#6 equator, t=193 ~ 204 deg

1mm

1.5mm

t=198 deg

t=199 deg

group of beads(?) with 1.5mm wide were observed.

13

0 360 deg180 90 270

#1

#2

#7

#6

#5

#4

#3

#9

#8

#1-#2i

#2-#3i

#3-#4i

#4-#5i

#5-#6i

#6-#7i

#7-#8i

#8-#9i

Group of spot

Scratch

Z110 summary

08/05/12

Iris

equator

T-map Heat spot

cell equator

Iris

14

0 360 deg180 90 270

#1

#2

#7

#6

#5

#4

#3

#9

#8

#1-#2i

#2-#3i

#3-#4i

#4-#5i

#5-#6i

#6-#7i

#7-#8i

#8-#9i

Group of spot

Scratch

Z111 summary

08/05/15

Iris

equator

T-mapHeat spot

cell equator

Iris



DESY Current Production:Comparison of Final Treatment

0

2

4

10 15 20 25 30 35 40

Eacc[MV/m]

# o

f ca

viti

es

BCP

EP




0123456

no.

of

cavi



0123456

no.

of

cavi



0123456

<16 16-18 18-20 20-22 22-24 24-26 26-28 28-30 30-32 32-34 34-36 36-38 38-40 40-42Gradient [MV/m]

no.

of

cavi


BCP ("EP+"): Emax



0

2

4

10 15 20 25 30 35 40

Eacc[MV/m]

# of

cav

ities

BCP

EP

DESY Current Production:Comparison of Final Treatment

Optical Inspection next

Camera Inspection Study of the STF TESLA-shape cavity #6

2008/3 : EBW parameter was decided by inspecting dumbbell EBW test samples.

2008/6 : STF TESLA-shape cavities #5 and #6 fabrication was completed.

The first inspection by using Kyoto camera (After fabrication)

2008/7 : Pre-EP (5 um) and EP-1 (20 um), Total removed about 25 um.

The second inspection by using Kyoto camera (After Pre-EP and EP-1)

2008/8 : 2nd EP-1 (100 um), Total removed about 25 um + 100 um

The third inspection by using Kyoto camera (After EP-1)

Five cat's eyes pits were found at equator,

and Three cat's eyes pits were found at iris at STF TESLA-shape #6 cavity.

*STF Baseline #5 cavity will be inspection from Sept. 15

Measured line

1500 um

1mm

-100

-50

0

50

100

0 500 1000 1500

STF baseline #6 cavityAfter EP-1 (25 + 100 um removed)

#2 cell equator Z=285mm t=198deg

Height [um] (100)

He

igh

t [u

m]

Z-axis [um]

Cavity wall side

Cavity vac.side

-30

-20

-10

0

10

20

0 500 1000 1500

STF baseline #6 cavityAfter EP-1 (25 + 100 um removed)

#2 cell equator Z=285mm t=198deg

Height [um] (100)

He

igh

t [u

m]

Z-axis [um]

Cavity wall side

Cavity vac.side

STF Baseline #6 cavity : #2 cell equator, Z=286mm, t=198 deg

EP-1 (25 + 100 um removed)

After Fabrication EP-1 (25 um removed)

Comparison with each treatment #2 cell equator, Z=286mm, t=198 deg

1 2

3

1mm

Measured line

1500 um

STF Baseline #6 cavity : #6 cell equator, Z=746mm, t=283 deg

-30

-20

-10

0

10

20

0 500 1000 1500

STF Baseline #6 cavityAfter EP-1 (25um + 100um removed)

#6 equator Z=746mm, t=283 deg.

Height [um] (100)

He

igh

t [u

m]

Z-axis [um]

-100

-50

0

50

100

0 500 1000 1500

STF Baseline #6 cavityAfter EP-1 (25um + 100um removed)

#6 equator Z=746mm, t=283 deg.

Height [um] (100)

He

igh

t [u

m]

Z-axis [um]

Cavity wall side

Cavity vac.side

EP-1 (25 + 100 um removed)

After Fabrication EP-1 (25 um removed)

Comparison with each treatment #6 cell equator, Z=746mm, t=283 deg



Where are we?

• Production issues– Low-gradient cavities show defects found by

temperature map and optical inspection– Training of manufacturers is mandatory

• Preparation issues– Have less impact currently

• Rinses developped within ILC R&D are successful– Ethanol (DESY), Ultrasound (JLab), Short EP (KEK)

• Clear path forward– Apply high resolution inspection

systematically to improve weld quality– Apply optimum surface preparation e.g.

ethanol rinse

Inspection Camera Status

KEK: 2 camera fabricated proto-type: under upgrading production-type #1: 1 year loan to DESY ( now at DESY ) ( 1 camera for US was proposed to US-JPN budget supplement, however it was not approved. )

production company contact was published to key players.

JLab: LDM system ( Questar telescope + mirror system ) was developed.

JLab LDM with T-map

JLab LDM Analysis

5/1/08, Rongli Geng JLab/KEK/FNAL S0 meeting

ACCEL8 (32 MV/m) Equator

4th Cell from FPC

ACCEL8 (32MV/m) Equator

2nd Cell from FPC

Guided Repair Development StatusKEK: Local mechanical grinding

Try to apply Ultrasonic tooling, micro-powder grinding, micro-powder buffing, to sample Nb plate. Insertion Mechanics is under design.

JLab: Surface re-melting by EBW from outside. Try to apply re-melting to sample Nb plate with intentional pits.

Rinse Development StatusDESY: Ethanol Rinse

JLab: Degreaser with ultrasonic KEK: Ethanol Rinse, Degreaser, H2O2 rise system are under developing.

Sponge wipe is under evaluating by JLab collaboration. Mechanics is under design.

Sample#1 Sample#2 (sponge wipe applied)

Lots of Nb-O particles (white)

Significantly reduced Nb-O particles

preliminary sample test

wipe test for sample in single-cell

Global Design Effort 294.4.2008 Lutz LiljeILC Project@DESY


ILC S0 Feedback LoopCavity Incoming QC

Countermeasure(Guided Repair)

Huge Irregularitieseg. Scratches

Feedback:Improve

Specification/QC

Standard Cavity Preparation Cycle

Identify Irregularitieseg. pits

Standard Vertical Test Cavity

Horizontal Tests or Module Assembly

Additonal Processing Cycle

Understand nature of high gradient limitation

e.g. does minor EP move quench location

Single Cells

WitnessSamples

Samples

> XX MV/m

< XX MV/m

Standard Vertical Test Cavity

S0 Status H. Hayano


Summary of S0 status

1. Cavity tests with optical inspection are come to standard procedure in KEK, JLab and DESY.

2. QC of EBW is recognized as important and inevitable. ( KEK has already started to instruct company. )

3. Guided repair tools are under developing.

4. Rinse studies are under progressing.

global design effort 1 s0 status high-gradient cavities lutz lilje desy supplement by h. hayano...

Documents

kek slide

field emission slide

z110 z111 slide

mhi i9

field emission analysis

desy current production

cell equator tmap data

mvm group of beads