 Cosmic data 2008  Cosmic data 2009  Collision data dec 2009Nikhef Jamboree, N. Tuning1/33 The Outer Tracker 1.Hardware status 2.Space Alignment 3.Time Alignment 4.Event distributions 5.Ageing

Interaction Point Muon System Calorimeters Tracking System Vertex Locator RICH Detectors The LHCb Detector 15 dec 20092/20Nikhef Jamboree, N. Tuning

Interaction Point Muon System Calorimeters Tracking System Vertex Locator RICH Detectors The LHCb Detector 15 dec 20093/20Nikhef Jamboree, N. Tuning

15 dec 2009Nikhef Jamboree, N. Tuning4/33 Outer Tracker 34 cm Total nr of channels: One module:  34 x 490 cm 2  4 x 64 = 256 straw tubes 5 m

15 dec 2009Nikhef Jamboree, N. Tuning5/20

 ~98% channels functional ! Huge Nikhef effort: Tom, Albert, Ad, + ½ of PhDs in bfys group Hardware status DAQ  99% of FE electronics running fine  4 (432) disabled FE boxes (replace in Jan)  0.22% noisy channels (without HV) not much extra noise with HV on 90% noisy channels in 2% of FE LV and HV  LV: 2(912) fuses blown, replaced  HV: 7(1680) channels have HV trips  HV power supplies: CAEN upgrades units from 0.2 mA to 3 mA max currents Gas System Prepare to add 1-2% O 2 15 dec 20096/33Nikhef Jamboree, N. Tuning

The road to where we are now: Cosmics 15 dec 2009Nikhef Jamboree, N. Tuning7/33 Debug DAQ Software Framework Noise Spacial alignment Time alignment Jan Amoraal, Thomas Bauer, Besma M’Charek, Roel Aaij

Cosmics: commission detector 15 dec 2009Nikhef Jamboree, N. Tuning8/ collisions cosmics cosmics Hitmap:  Holes are filled up in due time Top view: Jan Amoraal

15 dec 2009Nikhef Jamboree, N. Tuning9/10 Alignment 1)Positioning of OT  Special attention to avoid rotations  Carefully checked reproducibility  At nominal to <1.5(3) mm in x(z) 2)Knowing position  Survey accuracy to <0.5 mm 3)Software Alignment Antonio Pellegrino

Alignment: framework 15 dec 2009Nikhef Jamboree, N. Tuning10/33 LHCb alignment framework developed by Wouter, Gerhard and Jan  Implemented generically for all subdetectors  Extract misalignment from residual histograms  Need to deal with correlations  Minimal chi-square method  Minimize chi-square simultaneously wrt. alignment parameters and track parameters Find track parameters a: With n tracks, find alignment parameters β: Complication…  Some combination of parameters are poorly constrained: ‘weak modes’ Jan Amoraal, Wouter Hulsbergen, Gerhard Raven

Alignment: results (cosmics 2008) 15 dec 2009Nikhef Jamboree, N. Tuning11/20 Internal alignment of OT C-frames  Fix 2 C-frames, align the rest  Good agreement with survey Modules  Allow modules to move within C-frame  Checked consistency by splitting sample Ready for beam! Odd/even evt nr Forward/backward Full detail in Jan Amoraal’s thesis! Jan Amoraal A-sideC-side A-sideC-side

Alignment: collisions 15 dec 2009Nikhef Jamboree, N. Tuning12/20 Framework well tested Now, try on collisions  Magnet on  Different track distribution Adjustments wrt. survey <1 mm ! T1 T2 T3 (IT) C-frames: Modules: ± 1 mm Wouter Hulsbergen Δx (mm)

Time alignment 15 dec 2009Nikhef Jamboree, N. Tuning13/20 Hardware: hit needs to fall in readout window… Raw time drift time particle Hits Dec 2009 Hits Miss events! Raw time Nov 2009 Shift Software: determine t 0 constants Drift Time (ns) Distance (mm) 5 mm ~45 ns t0t0 Module t 0 (ns) (Slope comes from time of flight) Aleksandr Kozlinskiy,

15 dec 2009Nikhef Jamboree, N. Tuning14/20 A look at collision data

15 dec 2009Nikhef Jamboree, N. Tuning15/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning16/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning17/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning18/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning19/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning20/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning21/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning22/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning23/20 Roel Aaij

A look at collision data: alignment 15 dec 2009Nikhef Jamboree, N. Tuning24/33 m=497.3±0.6 MeV K s : close enough to the PDG… PDG

A look at collision data: Drift time 15 dec 2009Nikhef Jamboree, N. Tuning25/20 ~80k events from 11 Dec 2009 Drift time as expected  Inside readout window of 75ns  Max drift time ~45ns T1 T2 T3 T1T2 T3 Raw TDC Calibrated Drift Time 75 ns ~45 ns t meas =t drift +t tof +t prop +t 0

A look at collision data: Occupancy 15 dec 2009Nikhef Jamboree, N. Tuning26/20 Very few holes Every hole is understood Will be fixed in January More hits close to the beampipe T1T2T3 Zoom T1 T2 T3

A look at collision data: Efficiency 15 dec 2009Nikhef Jamboree, N. Tuning27/33 Check for hit if predicted by track Monitor plateau efficiency r<1.3 mm Average efficiency over detector >96% 2.45 mm Straw length  Wire locators Herve Terrier

A look at collision data: Efficiency 15 dec 2009Nikhef Jamboree, N. Tuning28/20 98% of detector working! Three handful FE-modules have problems: T1T2T3 Herve Terrier

Long track Upstream track Downstream track T track VELO track A look at collisions: Track types in LHCb 15 dec 2009Nikhef Jamboree, N. Tuning29/33 Long Tracks  highest quality for physics Downstream Tracks  K s finding Upstream Tracks  for RICH1 pattern recognition T Tracks  for RICH2 pattern recognition VELO Tracks  for Primary Vertex reconstruction

A look at collisions: Event distributions as expected 15 dec 2009Nikhef Jamboree, N. Tuning30/20 Nr of tracks with OT / event Nr of tracks / event Nr of OT hits / event Z Vertex (mm) Area normalized No beam-gas correction applied

A look at collisions: OT Track distributions as expected 15 dec 2009Nikhef Jamboree, N. Tuning31/33 Pseudo-rapidity (in T-stations) Momentum (MeV) All tracks with T-segment Area normalized (scaled by +20%)

Ageing 15 dec 2009Nikhef Jamboree, N. Tuning32/20 It’s the di-isopropyl-naphthalene (CAS ) inside the glue AY103-1  AY105 does not contain any plastifier  Just produced one module with AY105 Decided to add 1.5% O 2 to gas Large currents cure!  HV=1900V : large dark currents / discharges  HV=1800V, with source scanning over damage  Increase argon  Heating also cures  same process? After HV scan area  Is it feasible to just crank up the HV during beam for a few hours?  Can the power supplies handle such an instable situation of huge HV + LHC beam? Barbara Storaci, Daan van Eijk + 3 masters: Ivan Mous. Mathieu Blom, Erwin Visser

Summary Electronics in good shape Alignment close to design requirement Ageing stays a worry 15 dec 2009Nikhef Jamboree, N. Tuning33/33 Data archiving and re-analysis Data quality monitoring with reconstructed quantities  Tracking  Efficiency algorithm (also for ageing detection) Continue comparison data / MC Outlook

Backup 15 dec 2009Nikhef Jamboree, N. Tuning34/20

Efficiency: compare data/MC 15 dec 2009Nikhef Jamboree, N. Tuning35/20 Data: MC: Wire locators Y (A.U) FE moduleX (pitch) Y (A.U) FE moduleX (pitch) Eff lower close to beampipe, due to higher occupancy? Ionization length 325um instead of 850 um Plateau includes dead channels

Occupancy per Quarter 15 dec 2009Nikhef Jamboree, N. Tuning36/20 “Discrete” due to nr of tracks, 1,2,3, …

15 dec 2009Nikhef Jamboree, N. Tuning37/18 Beam Test r (mm) Drift time (ns) rt-relation: 2.45 mm r (mm) Efficiency, ε efficiency profile:  Resolution and efficiency for different HV and amplifier threshold

1) Reminder: effect of O 2 on ageing 30 Nov 2009LHCb week - N.Tuning38/10 What is the optimal amount of oxygen?  Beneficial effect of O 2 presumably due to ozone production  Ozone production maximal above 1% O 2  Between 1% and 4% no difference in ageing rate 1% O 2 NB: Need to disentangle effect of flushing time from fraction of O 2

30 Nov 2009LHCb week - N.Tuning39/10 2) Effect on Gain 0% O 2 2.5% O 2 4.5% O mV 319 mV 229 mV → Summarized in LHCb Effects of Adding Oxygen to the Outer Tracker Gas Mixture → Shown by Mathieu Blom in LHCb week 24 Nov Nov 2008 Addition of O 2 to gas mixture reduces gain by ~20%:  2.5% O 2 lowers response to 90 Sr by 20%  2.5% O 2 lowers 55 Fe pulse height by 10%  Confirmed by Dirk, Yuri, Christian with O 2 in test chamber in the pit Relative gain ? Average path length is same for 5.9keV γ from 55 Fe and 1MeV β from 90 Sr 55 Fe 90 Sr

2) Effect on Gain (Erwin) 30 Nov 2009LHCb week - N.Tuning40/10 What is fraction of clusters that reaches the wire?  r (cm)  Cluster survival probability 0% O 2 Avg.=86% 1% O 2 Avg.=76% 2% O 2 Avg.=67% 3% O 2 Avg.=59%  Simulations agree with 90 Sr Gain loss wrt 0% O 2 : 90 Sr 55 Fe Simulation Magboltz/Garfield simulations  2% O 2 gives average gain loss of 22% compared to 0% O 2  Gain loss ranges from 42% at r=2.5mm to 0% at r=0mm

3) Effect on Hit efficiency 30 Nov 2009LHCb week - N.Tuning41/27 What is probability that 0 clusters reach wire?  Use λ effective =850 µm Simulations agree with testbeam (λ effective =850 µm fits testbeam best) Ar/CO 2 70/302% O 2 >5% loss for r>1.9mm >5% loss for r>1.5mm Magboltz/Garfield simulations

15 dec 2009Nikhef Jamboree, N. Tuning42/10

15 dec 2009Nikhef Jamboree, N. Tuning43/20 Roel Aaij

15 dec 2009Nikhef Jamboree, N. Tuning44/20 Roel Aaij