13 Oct 2006Ageing Meeting Geneva, Niels & Gras1/15 NIKHEF update 3 lines of attack: 1)Heating (Mod...

13 Oct 2006 Ageing Meeting Geneva, Niels & Gras 1/15

NIKHEF update

3 lines of attack:1) Heating (Mod 30)

• 3 days at 45 C, 4 days at 48 C• Q1: Change in geometry, gas tightness,

gain?• Q2: Effect on ageing?

2) Flushing (Mod 2)• Improves rapidly, but suddenly worse• Q: why??

3) HV training (Mod 3)• Damage reappears after 200 hrs• Q: 200hrs of irradiation, or time constant?

Thanks to Edwin & Besma


Conclusions

Bad news

1) Heating• We can not confirm beneficial effect of heating

2) Flushing• Effect of flushing is temporary!• Due to opening of module??

• Pollution? Oxygen? Humidity?

3) HV training• It only seems to prevent ageing for subsequent 200 hrs of

flushing• Not completely understood:

• It cures and prevents ageing at irradiated spots• Can it also prevent ageing on unirradiated spots?


1) Heating Mod 30Setup


1) Heating Mod 30Temperature: 1st heating 3

daysProcedure1) Module 30 is heated

while flushing with CO2

2) One day at 35C3) 3 days at 48 C4) 4 days at 48 C

Logbook

22-29Sep Measure dimension, gas tightness

29Sep 35C 1 day

29Sep-2 Oct

48C 3 days

2-4 Oct Measure dimension, gas tightness

4 Oct Flush 24 hrs, then irradiate

6-10 Oct 48C >4 days

10 Oct Measure dimension, gas tightness


Sep29

Oct 2


1) Heating Mod 30Temperature: 2nd heating 4

daysProcedure1) Module 30 is heated

while flushing with CO2

2) One day at 35C3) 3 days at 48 C4) 4 days at 48 C

Logbook

22-29Sep Measure dimension, gas tightness

29Sep 35C 1 day

29Sep-2 Oct

48C 3 days

2-4 Oct Measure dimension, gas tightness


6-10 Oct 48C >4 days

10 Oct Measure dimension, gas tightness


Oct 5

Oct 6


1) Heating Mod 30Geometry: Flatness

Flatness:• Module is flat to +/- 200 μm• Change after heating <100 μm

33.0

33.5

34.0

34.5

35.0

0 1 2 3 4 5 6 7 8

Y (sticker)

Z (

mm

) Row III

Row II

Row I

33.0

33.5

34.0

34.5

35.0

0 1 2 3 4 5 6 7 8

Y (sticker)

Z (

mm

) Row III

Row II

Row I

Before After

Row III II I


1) Heating Mod 30Geometry: Length

Length:• Module shrinked by 1.03±0.10mm• Module shrinked by additional 0.38±0.10mm

These shifts are easily seen by eye…

Date a b Average (a+b)/2Nominal: 2.46mm

Delta

22Sep

3.69 2.88 3.28 +0.82

25Sep

3.55 3.21 3.38 +0.92

3 Oct 2.74 2.03 2.38 -0.08

5 Oct 2.27 2.16 2.21 -0.25

10 Oct

2.30 1.55 1.92 -0.54

12.92mm

8.0mma

b

moduletable

a+b/2


1) Heating Mod 30Geometry: Width

Width:• Module shrinked by 100 μm +/- 50

μm

Average width of module

339.40

339.50

339.60

339.70

339.80

339.90

340.00

340.10

340.20

340.30

1 2 3 4 5 6 7

sticker number

wid

th (

mm

)


1) Heating Mod 30Geometry: Shape

Before

After Consistency check of decreased width:~ -100μm

Shape:• Straight within +/-100μm


1) Heating Mod 30Gas Tightness

Before

1st heating

2nd heating

Date Leakage Flow (l/s)

22Sep

1.5 10-5

25Sep

1.1 10-5

3 Oct 2.8 10-5

5 Oct 0.4 10-5

10 Oct

4.0 10-5

10 Oct

1.8 10-5Gas tightness:• OK, Unchanged: 1.5 10-5 l/s ± 1.5 10-5 l/s• Corresponding to 0.007mb/min


1) Heating Mod 30

Ageing

Sep 4, after 6 days of flushing

Sep 19, after HV training

Oct 4, after 3 days at 48 C

Ageing:• No sign of improvement

after 3+4 days at 48 C!• Module became very noisy??

Oct 11, after 3+4 days at 48 C

Scan after

Scan before


Conclusions:

• Module 30 follows initial pattern from mod 2• What happened with module 2 ??

Briefly opened when moved from setup to setup Gas had finished before worsening of module 2 Flushing is only temporary benificial !? similar for heating??

2) Long term flushing

Module 63

36.2 m3

Compare to result from Heidelberg:

100 days

M002 ?!?

Heating of M030!?


2) Long term flushingdips in Module 3?

History: 21Mar – 12Apr:

28Mar-11Apr: opened module15Apr – 23May:

25Apr-10May: played with water bottle10May-15May: module not connected

23May – 19Jun: 6Jun: Change Ar bottle 6Jun – 19 Jun: Addition of O2

19Jun-15Aug20Jun-14Jul: module not connected

Mod

Date Loc I(nA)

Time (hrs)

1 3B 18Jan cleanroom

190 15

2 3B 23Feb

Lab 150 15

3 3B 21Mar

Lab 150 21.5

4 3B 12Apr

Lab 150 15

5 3A 15Apr

Lab 180 23

6 3A 23May

Lab 140 22

7 3A 19Jun Lab 150 16

8 3A 15Aug

Lab 150 2028Mar: opened moduleduring 14days

10May: opened moduleduring 5days

6Jun: flushed with 4% O2 for 13days

20Jun: opened moduleduring 24days


3) HV trainingGas flow

Conditions: Flow: Ar/CO2 70/30, 20 l/hr Irradiation: 2mCu, 90Sr source Sequence:

1) HV training ~40 hrs 1870 and 1920V2) Irradiate 340 hrs3) HV training 18 hrs 1910 V

Conclusions: A second HV training helps again

340 hrs

After HV

After HV

Lower?

2nd HV training

1st HV training

NB: 700 hrs ~ 2.5 106 s ~ 3 months nominal LHC

340+350 hrs

Rel

.gai

n

3rd HV training

Lower??


3) HV trainingQuestion:1) Does it prevent ageing during 200 hrs of irradiation2) Or does it prevent ageing for 200 hrs of flushing… It looks like 1) But untrained part improves!?

2nd HV training

1st HV training

3rd HV training

8 days of flushing

3 days of flushing

??

Gain indeed went upRatio 10Oct/3 Oct:

3Oct

29Sep-3Oct

10Oct


3) HV training

Question:• Is ageing also prevented at previously

unirradiated spots (pos. 190cm) ? Marginally…

• This seems in contradiction with measurements of Aug 20 on unirradiated spot (pos. 200cm)

20hrs

96hrs

Deepest point Integrated loss over surface


Conclusions

Bad news

1) Heating• We can not confirm beneficial effect of heating

2) Flushing• Effect of flushing is temporary!• Due to opening of module??

• Pollution? Oxygen? Humidity?

3) HV training• Not completely understood:

• It cures and prevents ageing at irradiated spots• Can it also prevent ageing on unirradiated spots??

– Contradicting results…

13 Oct 2006Ageing Meeting Geneva, Niels & Gras1/15 NIKHEF update 3 lines of attack: 1)Heating (Mod...

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