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Ageing studies since June 2006. Comparisons HD – NIKHEF damage, patterns, analyses Oxygen results Outgassing. 55 Fe Comparison NIKHEF – HD. Agreement?. HD. NIKHEF. Compare large area irradiation. HD: 9 keV X ray, radius ~50cm, 140 hrs, 50 nA (1520V): 80% damage
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Ageing studies since June 2006 Comparisons HD – NIKHEF damage, patterns, analyses Oxygen results Outgassing
55Fe Comparison NIKHEF – HD Agreement? HD NIKHEF
Compare large area irradiation • HD: 9 keV X ray, radius ~50cm, 140 hrs, 50 nA (1520V): 80% damage • NI: 2mCu 90Sr, radius ~30cm, 14 hrs, 50 nA (1600V): 10% damage • Both: damage upstream, • Both: more damage in the center of the module gas
Check region channel 1-10 • 3 measurements • Before irradiation • After irradiation • Rescan Ratio 2/1 Ratio 3/1 Ratio 3/2 ok lowish Conclusion: • Measurement 2 is suspiciously low around ch1-10 • The damaged area worsened from 0.3 to 0.25
Single wire • Disconnected all wire, but wire 32. • Conclusion: • Ageing occurs independent of neighbors • Possibly can use a simple test module of 1 straw to investigate materials • Spots at 20, 40, 50 cm unclear…
55Fe Comparison NIKHEF – HD Agreement? HD NIKHEF
90Sr Comparison NIKHEF - HD Agreement? HD NIKHEF
Analysis Comparison NIKHEF - HD Irradiation: 22hrs Ratio of gain NIKHEF analysis HD analysis Different definition of rings
Analysis Comparison NIKHEF - HD Irradiation: 30hrs Ratio of gain NIKHEF analysis HD analysis Different definition of rings
Small current 22 hrs, 125 nA 90Sr (test16) • Conditions: • Flow: Ar/CO2 20 l/hr • 1600V, 70/30, 90Sr • 22 hrs, 125 nA ~ 10mC • 166hrs, 2.5 nA ~ 1.5mC • Conclusions: • Maximum damage at small currents 166 hrs, 2.5 nA 90Sr Current profile:
Flush with Oxygen: Ar/CO2/O2 70/27.5/2.5 • Conditions: • 1600V, 90Sr • Ar/CO2 70/30 20 l/hr • Ar/CO2/O2 70/27.5/2.5 10 l/hr • Conclusions: • With oxygen slower ageing • NB. Gas flow is lower… 22 hrs, Ar/CO2 70/30 (test16) 66 hrs, Ar/CO2/O2 70/27.5/2.5 (test16) Current profile
Flush with Oxygen 68 hr @13cm Gas flow • Conditions: • Flow: Ar/CO2/O2 10 l/hr • 2mCu, 90Sr source Conclusions: • Oxygen ages slowly 68 hr @13cm 22 hr @23cm 68 hr @13cm 46 hr @23cm Compare to result from Heidelberg: 90 hr @13cm 46 hr @23cm
Flush with Oxygen,vary gas flow Ar/CO2 70/30, 46hrs, 20 l/hr • Conditions: • Flow: Ar/CO2/O2 70/27.5/2.5 % • 2mCu, 90Sr source, 68 hrs Conclusions: • Oxygen ages slower by factor 3 • Larger flow, larger ageing 10 l/hr 20 l/hr
Did oxygen flushing prevent ageing? After oxygen flushing, irradiated 16 hrs: • Test to prevent ageing • Conditions: • Flow: Ar/CO2 20 l/hr • 2mCu, 90Sr source on module surface, 16 hours • Conclusions: • Ageing as usual. • Irradiation after oxygen flushing does not prevent ageing gas U L No oxygen flushing, irradiated 22 hrs: Ratio Zoom
Long term? Outgassing? 3B (30) - 12/4/2006 – 15hr 3B (7) - 18/1/2006 - 15hr • Conditions: • Flow: Ar/CO2 70/30 20 l/hr • January: in cleanroom • Feb – now: in lab • 2mCu, 90Sr source 3A (3) - 15/4/2006 – 23hr 3B (17) - 23/2/2006 - 15hr 3B (28) - 21/3/2006 – 21.5hr 3A (19) - 23/5/2006 – 22hr
Long term?Outgassing? • Conditions: • Flow: Ar/CO2 70/30 20 l/hr • January: in cleanroom • Feb – now: in lab • 2mCu, 90Sr source 3A (3) - 15/4/2006 – 23hr 3B (7) - 18/1/2006 - 15hr 3B (17) - 23/2/2006 - 15hr 3A (19) - 23/5/2006 – 22hr 3B (28) - 21/3/2006 – 21.5hr 3A (27) - 19/6/2006 – 16hr 3A (29) - 15/8/2006 – 20hr 3B (30) - 12/4/2006 – 15hr
Damage vs Time(module 3) • Conditions: • Flow: Ar/CO2 70/30 20 l/hr • 2mCu, 90Sr source • January: in cleanroom • Feb – now: in lab • Flushed for 140 days • ~65,000 liter gas normalization? 15hr 16hr careful... Also the ‘tape region’ is integrated here! 15hr 16hr • Point 4,7 is a bit strange: • Only 15,16 hrs of irradiation • More damage
Ageing (22hr) before vacuum treatment Put 1m-module 1day, 6days under vacuum • Conditions: • Flow: Ar/CO2 70/30 • 2mCu, 90Sr source Conclusions: • Forced outgassing in vacuum helps?? Ageing (19hr) after vacuum treatment Ageing (19hr) after 6 days vacuum treatment Ageing (18hr) additional 50hrs flushing Note different scale!
Irradiating after reversing gas flow • Conditions: • Flow: Ar/CO2 70/30 • 2mCu, 90Sr source Conclusions: • Reversing gas flow makes little recovery Gas flow 84 hrs irradiation Netto effect: Gas flow 91 hrs irradiation
Additional damage after flushing?No irradiation! • Conditions: • Flow: Ar/CO2 70/30 • 2mCu, 90Sr source • Flush for 20 days at 20 l/hr between July 26 and August 15 Conclusions: • Additional damage after flushing Ratio of scans from Aug15 / Jul26 Original damage from irradiation:
Different F-module: 002Test effect of fast flushing • Conditions: • Flow: Ar/CO2 70/30 % • 2mCu, 90Sr source~20hrs • Flushing: • 140 l/hr • Total 21,000 l of N2 Conclusions: • Flushing helps • gas flow not important Ageing (19hr) before flushing Ageing (19hr) after 7,400 l flushing Ageing (21hr) after 21,000 l flushing
Damage vs TimeIrradiation profiles • Conditions: • Flow: Ar/CO2 70/30 20 l/hr • 2mCu, 90Sr source • Between 22Jun and Jul27: Flushed with N2 with 140 l/hr
Improvement with Time Jun 22 • Conditions: • Flow: Ar/CO2 20 l/hr • 2mCu, 90Sr source • Between 22Jun and Jul27: • Flushed with N2 with 140 l/hr Jun 28 Jul 4 Jul 27 Aug 28 Aug 15
Damage vs TimeCompare mod 2 and mod 3 • Conclusions: • Module 2 improves faster than module 3 3rd: 10% longer irr Compare to result from Heidelberg: Module 63 36.2 m3 100 days