Download - The Outer Tracker
![Page 1: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/1.jpg)
Cosmic data 2008 Cosmic data 2009 Collision data 2009
15 dec 2009 Nikhef Jamboree, N. Tuning 1/33
The Outer Tracker
1. Hardware status2. Space Alignment3. Time Alignment4. Event distributions5. Ageing
![Page 2: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/2.jpg)
InteractionPoint
Muon System
Calorimeters Tracking System
Vertex Locator
RICH Detectors
The LHCb DetectorThe LHCb Detector
15 dec 2009 2/20Nikhef Jamboree, N. Tuning
![Page 3: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/3.jpg)
InteractionPoint
Muon System
Calorimeters Tracking System
Vertex Locator
RICH Detectors
The LHCb DetectorThe LHCb Detector
15 dec 2009 3/20Nikhef Jamboree, N. Tuning
![Page 4: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/4.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 4/33
Outer Tracker
34 cm
Total nr of channels: 53.760
One module: 34 x 490 cm2
4 x 64 = 256 straw tubes
5 m
![Page 5: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/5.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 5/20
![Page 6: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/6.jpg)
~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% O2
15 dec 2009 6/33Nikhef Jamboree, N. Tuning
![Page 7: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/7.jpg)
The road to where we are now: Cosmics
15 dec 2009 Nikhef Jamboree, N. Tuning 7/33
• Debug DAQ• Software
Framework• Noise• Spacial alignment• Time alignment
Jan Amoraal, Thomas Bauer, Besma M’Charek, Roel Aaij
![Page 8: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/8.jpg)
Cosmics: commission detector
15 dec 2009 Nikhef Jamboree, N. Tuning 8/20
2009 - collisions
2009 - cosmics
2008 - cosmics
• Hitmap: Holes are filled up in due time
Top view:
Jan Amoraal
![Page 9: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/9.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 9/10
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
![Page 10: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/10.jpg)
Alignment: framework
15 dec 2009 Nikhef Jamboree, N. Tuning 10/33
• 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
![Page 11: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/11.jpg)
Alignment: results (cosmics 2008)
15 dec 2009 Nikhef Jamboree, N. Tuning 11/20
• 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 t
hesis!
Jan Amoraal
A-side C-side
A-side C-side
![Page 12: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/12.jpg)
Alignment: collisions
15 dec 2009 Nikhef Jamboree, N. Tuning 12/20
• Framework well tested• Now, try on collisions
Magnet on Different track distribution
• Adjustments wrt. survey <1 mm !
T1 T2 T3(IT) (IT) (IT)
C-frames:
Modules:±
1 m
mWouter Hulsbergen
Δx
(mm
)
![Page 13: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/13.jpg)
Time alignment
15 dec 2009 Nikhef Jamboree, N. Tuning 13/20
• Hardware: hit needs to fall in readout window…
Raw time
drift time
parti
cle
Hit
s
Dec 2009Hit
sMiss events! Raw time
Nov 2009
Shift
• Software: determine t0 constants
Dri
ft T
ime
(ns)
Distance (mm)
5 mm
~45
ns
t0
Mod
ule
t 0 (ns
)
(Slope comes from tim
e of flight)
Aleksandr Kozlinskiy,
![Page 14: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/14.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 14/20
A look at collision dataA look at collision data
![Page 15: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/15.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 15/20Roel Aaij
![Page 16: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/16.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 16/20Roel Aaij
![Page 17: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/17.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 17/20Roel Aaij
![Page 18: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/18.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 18/20Roel Aaij
![Page 19: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/19.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 19/20Roel Aaij
![Page 20: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/20.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 20/20Roel Aaij
![Page 21: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/21.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 21/20Roel Aaij
![Page 22: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/22.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 22/20Roel Aaij
![Page 23: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/23.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 23/20Roel Aaij
![Page 24: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/24.jpg)
A look at collision data: alignment
15 dec 2009 Nikhef Jamboree, N. Tuning 24/33
m=497.3±0.6 MeV
• Ks: close enough to the PDG…
PDG
![Page 25: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/25.jpg)
A look at collision data: Drift time
15 dec 2009 Nikhef Jamboree, N. Tuning 25/20
• ~80k events from 11 Dec 2009• Drift time as expected
Inside readout window of 75ns Max drift time ~45ns
T1
T2
T3T1 T2 T3
Raw
TD
CC
alib
rate
d D
rift
Tim
e
75 ns
~45 ns
tmeas=tdrift+ttof+tprop+t0
![Page 26: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/26.jpg)
A look at collision data: Occupancy
15 dec 2009 Nikhef Jamboree, N. Tuning 26/20
• Very few holes• Every hole is understood• Will be fixed in January
• More hits close to the beampipe
T1 T2 T3
Zoom Zoom Zoom
T1
T2
T3
![Page 27: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/27.jpg)
A look at collision data: Efficiency
15 dec 2009 Nikhef Jamboree, N. Tuning 27/33
• 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
![Page 28: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/28.jpg)
A look at collision data: Efficiency
15 dec 2009 Nikhef Jamboree, N. Tuning 28/20
• 98% of detector working!• Three handful FE-modules have
problems:
T1 T2 T3
Herve Terrier
![Page 29: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/29.jpg)
Long track
Upstream track
Downstream track
T track
VELO track
A look at collisions: Track types in LHCb
15 dec 2009 Nikhef Jamboree, N. Tuning 29/33
Long Tracks highest quality for physicsDownstream Tracks Ks finding
Upstream Tracks for RICH1 pattern recognition
T Tracks for RICH2 pattern recognition
VELO Tracks for Primary Vertex reconstruction
![Page 30: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/30.jpg)
A look at collisions: Event distributions as expected
15 dec 2009 Nikhef Jamboree, N. Tuning 30/20
Nr of tracks with OT / event
Nr of tracks / event Nr of OT hits / event
Z Vertex (mm)
Area normalizedNo beam-gas correction
applied
![Page 31: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/31.jpg)
A look at collisions: OT Track distributions as expected
15 dec 2009 Nikhef Jamboree, N. Tuning 31/33
Pseudo-rapidity (in T-stations) Momentum (MeV)
All tracks with T-segmentArea normalized (scaled by
+20%)
![Page 32: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/32.jpg)
Ageing
15 dec 2009 Nikhef Jamboree, N. Tuning 32/20
• It’s the di-isopropyl-naphthalene (CAS
38640-62-9) inside the glue AY103-1 AY105 does not contain any plastifier Just produced one module with AY105
• Decided to add 1.5% O2 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
![Page 33: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/33.jpg)
SummarySummary• Electronics in good shape• Alignment close to design requirement• Ageing stays a worry
15 dec 2009 Nikhef Jamboree, N. Tuning 33/33
• Data archiving and re-analysis• Data quality monitoring with reconstructed
quantities Tracking Efficiency algorithm (also for ageing detection)
• Continue comparison data / MC
OutlookOutlook
![Page 34: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/34.jpg)
Backup
15 dec 2009 Nikhef Jamboree, N. Tuning 34/20
![Page 35: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/35.jpg)
Efficiency: compare data/MC
15 dec 2009 Nikhef Jamboree, N. Tuning 35/20
• Data:
• MC:
Wire locators
Y (A.U) FE moduleX (pitch) X (pitch)
Y (A.U) FE moduleX (pitch) X (pitch)
Eff lower close to beampipe , due tohigher occupancy?
Ionization length 325um instead of 850 um
Plateau includesdead channels
![Page 36: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/36.jpg)
Occupancy per Quarter
15 dec 2009 Nikhef Jamboree, N. Tuning 36/20
“Discrete” due to nr of tracks, 1,2,3, …
![Page 37: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/37.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 37/18
Beam Test
r (mm)
Dri
ft ti
me
(ns)
rt-relation:
2.45 mm 2.45 mm
r (mm)
Eff
icie
ncy,
ε
efficiency profile:
Resolution and efficiency for different HV and amplifier threshold
![Page 38: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/38.jpg)
1) Reminder: effect of O2 on ageing
30 Nov 2009 LHCb week - N.Tuning 38/10
• What is the optimal amount of oxygen? Beneficial effect of O2 presumably due to ozone production
Ozone production maximal above 1% O2
Between 1% and 4% no difference in ageing rate
1% O2
NB: Need to disentangle effect of
flushing time from fraction of O2
![Page 39: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/39.jpg)
30 Nov 2009 LHCb week - N.Tuning 39/10
2) Effect on Gain
0% O2 2.5% O2 4.5% O2
286 mV319 mV 229 mV
→ Summarized in LHCb-2008-064Effects of Adding Oxygen to the Outer Tracker Gas Mixture
→ Shown by Mathieu Blom in LHCb week 24 Nov 2008
• Addition of O2 to gas mixture reduces gain by ~20%: 2.5% O2 lowers response to 90Sr by 20%
2.5% O2 lowers 55Fe pulse height by 10%
Confirmed by Dirk, Yuri, Christian with O2 in test chamber in the pit
Relative gain
? Average path length is same for 5.9keV γ from 55Fe and 1MeV β from 90Sr
55Fe 90Sr
![Page 40: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/40.jpg)
2) Effect on Gain (Erwin)
30 Nov 2009 LHCb week - N.Tuning 40/10
What is fraction of clusters that reaches the wire?
r (cm)
C
lust
er s
urvi
val p
roba
bili
ty
0% O2
Avg.=86%1% O2
Avg.=76%
2% O2
Avg.=67%3% O2
Avg.=59%
Simulations agree with 90Sr
Gain loss wrt 0% O2: 90Sr55Fe
Simulation
Magboltz/Garfield simulations
2% O2 gives average gain loss of 22% compared to 0% O2
Gain loss ranges from 42% at r=2.5mm to 0% at r=0mm
![Page 41: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/41.jpg)
3) Effect on Hit efficiency
30 Nov 2009 LHCb week - N.Tuning 41/27
What is probability that 0 clusters reach wire?
Use λeffective=850 µm
Simulations agree with testbeam
(λeffective=850 µm fits testbeam best)
Ar/CO2 70/30 2% O2
>5% loss for r>1.9mm >5% loss for r>1.5mm
Magboltz/Garfield simulations
![Page 42: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/42.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 42/10
![Page 43: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/43.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 43/20Roel Aaij
![Page 44: The Outer Tracker](https://reader038.vdocument.in/reader038/viewer/2022102911/56814749550346895db4885f/html5/thumbnails/44.jpg)
15 dec 2009 Nikhef Jamboree, N. Tuning 44/20Roel Aaij