19 Oct 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?

19 Oct ) Heating Mod 30 Setup

19 Oct ) Heating Mod 30 Temperature: 1 st heating 3 days Procedure 1)Module 30 is heated while flushing with CO 2 2)One day at 35C 3)3 days at 48 C 4)4 days at 48 C Logbook 22-29SepMeasure dimension, gas tightness 29Sep35C1 day 29Sep-2 Oct48C3 days 2-4 OctMeasure dimension, gas tightness 4 OctFlush 24 hrs, then irradiate 6-10 Oct48C>4 days 10 OctMeasure dimension, gas tightness 10 OctFlush 24 hrs, then irradiate Sep29 Oct 2

19 Oct ) Heating Mod 30 Temperature: 2 nd heating 4 days Procedure 1)Module 30 is heated while flushing with CO 2 2)One day at 35C 3)3 days at 48 C 4)4 days at 48 C Logbook 22-29SepMeasure dimension, gas tightness 29Sep35C1 day 29Sep-2 Oct48C3 days 2-4 OctMeasure dimension, gas tightness 4 OctFlush 24 hrs, then irradiate 6-10 Oct48C>4 days 10 OctMeasure dimension, gas tightness 10 OctFlush 24 hrs, then irradiate Oct 5 Oct 6

19 Oct ) Heating Mod 30 Geometry: Flatness Flatness: Module is flat to +/- 200 μm Change after heating <100 μm Before After Row III II I

19 Oct ) Heating Mod 30 Geometry: Length Length: Module shrinked by 1.03±0.10mm Module shrinked by additional 0.38±0.10mm  These shifts are easily seen by eye… DateabAverage (a+b)/2 Nominal: 2.46mm Delta 22Sep Sep Oct Oct Oct mm 8.0mm a b module table a+b/2

19 Oct ) Heating Mod 30 Geometry: Width Width: Module shrinked by 100 μm +/- 50 μm

19 Oct ) Heating Mod 30 Geometry: Shape Before After Consistency check of decreased width: ~ -100μm Shape: Straight within +/-100μm

19 Oct ) Heating Mod 30 Gas Tightness Before 1 st heating 2 nd heating DateLeakage Flow (l/s) 22Sep Sep Oct Oct Oct Oct Gas tightness: OK, Unchanged: l/s ± l/s Corresponding to 0.007mb/min

19 Oct ) 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

19 Oct 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 m 3 Compare to result from Heidelberg: 100 days M002 ?!? Heating of M030!?

19 Oct ) Long term flushing dips in Module 3? History:  21Mar – 12Apr:  28Mar-11Apr: opened module  15Apr – 23May:  25Apr-10May: played with water bottle  10May-15May: module not connected  23May – 19Jun:  6Jun: Change Ar bottle  6Jun – 19 Jun: Addition of O 2  19Jun-15Aug  20Jun-14Jul: module not connected ModDateLocI(nA)Time (hrs) 13B18Jancleanroom B23FebLab B21MarLab B12AprLab A15AprLab A23MayLab A19JunLab A15AugLab Mar: opened module during 14days 10May: opened module during 5days 6Jun: flushed with 4% O 2 for 13days 20Jun: opened module during 24days

19 Oct ) HV training Gas flow Conditions:  Flow: Ar/CO 2 70/30, 20 l/hr  Irradiation: 2mCu, 90 Sr source  Sequence: 1)HV training ~40 hrs 1870 and 1920V 2)Irradiate 340 hrs 3)HV training 18 hrs 1910 V Conclusions:  A second HV training helps again 340 hrs After HV Lower? 2 nd HV training1 st HV training NB: 700 hrs ~ s ~ 3 months nominal LHC hrs Rel.gain 3 rd HV training Lower??

19 Oct ) HV training Question: 1)Does it prevent ageing during 200 hrs of irradiation 2)Or does it prevent ageing for 200 hrs of flushing…  It looks like 1)  But untrained part improves!? 2 nd HV training1 st HV training3 rd HV training 8 days of flushing 3 days of flushing ?? Gain indeed went up Ratio 10Oct/3 Oct: 3Oct 29Sep -3Oct 10Oct

19 Oct ) 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

19 Oct ) Heating Mod 30: high currents cured? After heating: many channels with high current 1)Loose wire tension? (shorter module?) 2)Loose wire tension? (loose soldering?) 3)Deformation of straw? 4)Humidity in module? 5)Broken feedthrough board? After additional 3 days of flushing: high currents disappeared! Scan after heating: Scan after heating and additional 3 days of flushing:

19 Oct Development of Currents: ch1; the side

19 Oct Development of Currents: ch64; the side

19 Oct Development of Currents: ch33; irradiated

19 Oct Development of Currents: ch27; ?

19 Oct ) 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 Oct 16, 7days heating +4days flushing

19 Oct Ageing after Heating+Flushing Ageing: No sign of improvement after 3+4 days at 48 C Some improvement after flushing, but is it more than expected?  Slope is nicely steep  But is there a factor 5? 3+4 days heating +4 days flushing 3+4 days heating (heated module)

19 Oct A closer look: compare (using deepest point definition) 3+4 days heating +4 days flushing 3+4 days heating Conclusion? 11 days heating +3 days flushing Heidelberg 17 days heating

19 Oct A closer look: compare using HD definition 3+4 days heating +4 days flushing 3+4 days heating HD: ~90hrs 55 Fe NI: ~20hrs 90 Sr Conclusion? Is there a steeper slope when we heat ? 11 days heating +3 days flushing Heidelberg 17 days heating

19 Oct Summary HD – NIKHEF data HD: ~90hrs 55 Fe Mod 20 and Mod 7 heated Mod 7: 186 hr irradiation! NI: ~20hrs 90 Sr Mod 20+7 have steeper slope?? NB: Mod 7 2x the irradiation Mod 7 Mod 20

19 Oct m Module: an oldy… What is the 3.2m module?  Construction date: 2001  Used in 2001 testbeam for TDR  Straws glued to panels with Araldite or Stycast?? 16 channels connected LHCb

19 Oct Irradiating 3.2m Mod 20 hrs hrs 23 hrs 118 hrs Gas flow Two irradiations, 2 mCu  44 hrs  118 hrs  very little damage 164 hrs

19 Oct Irradiation 3.2m Mod  very little damage  3.2m: 15% after 200hrs  Mod3: 35% after 200hrs Progressing in time Independent of definition Compare to F-mod 3: 3.2 m module (2001):