MB validation with Cosmic Rays

1
A. Meneguzzo Padova University INFN
Validation and Performance of the CMS Barrel
Muon Drift Chambers with Cosmic Rays
Cosmic rays are free, have no schedule ,
illuminate uniformly, are in all production
sites.....
Each chamber of the Barrel Muon System of the
CMS experiment equipped with the final front-end
and Low and High Voltage boards is fully tested
in each assembly site in a cosmic rays facility.
The system allows to check in real time the
perfomances and the quality of the chambers and
of the local trigger devices.The behaviour of the
chambers built in the Legnaro INFN National Lab
is reported and compared with Test Beam results.
2
Barrel muon system
V.Monaco INFN Torino 8th
IACTPP Conference, Como 6-10 October 2003
5 wheels
30o sectors with 4 stations
250 DT chambers 2.0x2.5 m2 (MB1) 4.0x2.5 m2
(MB4) 2105 channels
480 RPC chambers
MB4
MB3
MB2
MB1
3
CMS Drift Tube Chambers
Within one SL 4 layers staggered by half a cell
to solve L/R ambiguity
42mm
A
S
S
B
13mm
13mm
W
W
g
g
s
s
C
a
b
a
b
b/a .65
b/a .65
D
continuous lines represent electrodes
dotted lines represent equipotential surfaces
continuous lines represent electrodes
dotted lines represent equipotential surfaces
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Muon system specifications
V.Monaco INFN Torino 8th
IACTPP Conference, Como 6-10 October 2003
Muon identification (after gt10 ? up to ? ? 2.4)
Standalone momentum measurement
Charge assignement (up to few TeV)
Trigger on single and di-muons with variable Pt
threshold up to ??2.1
Bunch crossing assignment
5
Laboratori Nazionali di Legnaro (padova) DT
chambers construction
glue for I-beam
LNL
Final chamber
HV LV boards
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Barrel Muon DT chamber requirements

• drift time vs position linearity in the cell
• 100mm precision on wire position within a SL
• lt1mm between f SL

• First Level Trigger
• (Mean time technique on staggered layers)
• Bunch crossing identification
• Track segment reconstruction
• Pt cut sharp efficiency curve

• Resolution of 250mm/cell
• Max Efficiency
• Minimum Noise level

Muon track parameter - muon ID coverage up
to IhI1.1 - momentum charge assignement
Noise Efficiency Resolution Wire and Layer
position accuracy SL F position accuracy

we want to measure for each chamber
7
Chambers and Trigger set up at LNL
Chamber under test
Chamber under trigger test
Local Trigger CCB
Cosmic Rays trigger set-up
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Monitor and analysis SET UP
The DAQ system is developed within the TRIDAS
project it has been used in the Test Beam 2000 ,
2001, 2003 and at ISR (stoking area for final
checks of all DT chambers).
G.Maron et al. LNL
Data Base Objectivity Flat File
N.Toniolo LNL
Analisys Off-line -track
reconstruction -trigger emulator
-ntuples production with
raw data and tracks
information ORCA framework P.Ronchese et al.,
Pd
MONITOR on line analysis occupancy -noise
-efficiency -MT -Event Display ORCA
framework Sara.Vanini et al., PD
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Cell and drift time distribution checks
1800 V
Strips
3600V
good
-1200 V
bad but it can be recovered
Drift time
Bad cathod
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Noise
Noise of the channels in all layers of a
chamber of all chambers
channel
channel
20 Hz/m
11
Noise vs Hv and noise vs Th
Noise vs HV on the wire
Noise vs FrontEnd Threshold
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Efficiency
cell efficiency in the layer efficiency
inside the cell
geometrical inefficiency 1.2/42 3 for normal
tracks
I-beam
wire
1.00 0.96
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Efficiency angle all chambers
Dead angle 90
98
99
Mean SL Efficiency for the first 12 chambers
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Efficiency diagnostic
Efficiency in a layer last 8 cells low efficiency
Efficiency as a function of position inside the
cells
No voltage on the cathods
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Mean time fit with time
y
t4
t3
t2
21000/ 380ns Vdrift55mm/ns
t1
d staggering
s 1.6ns Wire position accuracy70mm
semicolumn
From the MeanTime distribution of the tracks in
each semicolumn (semicell) we measure -the wire
position accuracy from the width of the
distribution of the Mean
-the resolution and the resolution uniformity of
the cells along the layer and in the SL
Resolution250mm
Resolution smtsqrt((s2-s trig_pm2) 3/2sl2
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MT Layer displacement
Example layer 4 displaced of dx
Dt
Dt
t4
t4
t4
t4
t3
t3
t3
t3
Dt ( MT234R- MT234L) using the mean value of
all MT234 -gtgood accuracy Layer 4 displacement -gt
Dx Dt vdrift
t2
t2
t2
t2
t1
t1
t1
t1
d staggering
d staggering
d staggering
d staggering
Mean 378 ns
Mean 383 ns
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MT signal wire propagation
Measurement of the signal propagation along the
wire
vsignal0.244 m/ns
FEside
vdrift21/3780.55mm/ns
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MT summary
Resolution in the cell
Drift velocity in the cell
Accuracy on staggering and wire position s1.7 ns
gtgt 66 mm
For all chambers
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MT vs angle
The apparent drift velocity grows with y angleit
is constant for q
F angle
q angle
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F Super Layers alignment
All 4 point tracks, f lt 20o
622?15 mm
build 4 point segment in each single SL
MB3_12
x2
Extrapolate to the middle plane of the chamber
x1
-3.8?0.1 mrad
before alignment corrections
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Layer alignement 7 point fit residuals
ltgt-175?5 mm
SL f1
ltgt20?5 mm
MB3_12
ltgt39?5 mm
SL f2
ltgt65?5 mm
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C2 fit vs SLs displacement
c2 / NDOF
all but one layer included (before layer
alignment)
85?15 mm
Layer 1 excluded
before layer alignment
-0.5?0.1 mrad
all layers included
after layer alignment
after alignment corrections
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DT Chamber performance in Test Beam
Hit rate in SL1 is 3.5 (1.7 for SL 2) larger
than the worst case at LHC (shown SL1)
MB2 TEST BEAM 2001 Resolution and
Plateau knee
Drift cell effic.resolution With increasing
Background
CMS Note 2003/007
192 micron
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DT Chambers 1st Level Trigger
SL2 BTI outer
SL1 BTI inner
H 4 points track
L 3 points track
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First Level Trigger set-up functionality tests
with cosmic rays
The first final set up of the First Level Trigger
has been tested on a MB3 chamber with a muon
bunched beam at Cern in may 2003 (the test was
successfully and preliminary results show perfect
behaviour). The set up was first assembled and
its functionaly checked at the assembly site in
LNL. Here I presents the on line results of these
first preliminary tests that showed us that the
set up was correctly working. The real
performance of the 1st Level Trigger have been
studied on the test beam run and will come out
soon. (Results of the performance of the BTI part
of the 1st Level Trigger from Test Beam and with
Magnetic field are in the CMS note01-051)
output triggers with 3(L) or 4(H) hits trigger
tracks in each SL -gtcorrelated trigger
Bunch crossing identification
Angle trigger
-450
450
Angle track
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Bunched TB 2003 DTchamberTriggerPreliminary
Bunched TB 2003 DTchamberTriggerPreliminary
Bunched TB 2003 DTchamberTriggerPreliminary
trig. at 14bx efficiency
total of events Event
scintillator 2 hits in beam region
trig. at 14bx efficiency
total of events Event
scintillator 2 hits in beam region
trig. at 14bx efficiency
total of events Event
scintillator 2 hits in beam region
trig. at 14bx efficiency
total of events Event
scintillator 2 hits in beam region
trig. at efficiency
total of events Event scintillator
2 hits in beam region
tracks hitting 2 I-beams
tracks hitting 2 I-beams
tracks hitting 2 I-beams
tracks hitting 2 I-beams
tracks hitting 2 I-beams
Preliminary DT Trigger Performance - Sara Vanini
SIF 2003
98-99 efficiency up to 350
98-99 efficiency up to 350
98-99 efficiency up to 350
98-99 efficiency up to 350
98-99 efficiency up to 350
EMULATOR is a SW package that emulates the full
chain of the Trigger Chips and Boards. It works
offline and need as input the times recorded by
the TDCs. Emulator is not the CMS
simulation,it should reproduce exactly the
Trigger data. To compare with the expected
performance as shown in the Trigger TDR we
should compare with the full track reconstruction
from TDC data. However this first result is in
excellent agreement with what we expect.
EMULATOR is a SW package that emulates the full
chain of the Trigger Chips and Boards. It works
offline and need as input the times recorded by
the TDCs. Emulator is not the CMS
simulation,it should reproduce exactly the
Trigger data. To compare with the expected
performance as shown in the Trigger TDR we
should compare with the full track reconstruction
from TDC data. However this first result is in
excellent agreement with what we expect.
EMULATOR is a SW package that emulates the full
chain of the Trigger Chips and Boards. It works
offline and need as input the times recorded by
the TDCs. Emulator is not the CMS
simulation,it should reproduce exactly the
Trigger data. To compare with the expected
performance as shown in the Trigger TDR we
should compare with the full track reconstruction
from TDC data. However this first result is in
excellent agreement with what we expect.
EMULATOR is a SW package that emulates the full
chain of the Trigger Chips and Boards. It works
offline and need as input the times recorded by
the TDCs. Emulator is not the CMS
simulation,it should reproduce exactly the
Trigger data. To compare with the expected
performance as shown in the Trigger TDR we
should compare with the full track reconstruction
from TDC data. However this first result is in
excellent agreement with what we expect.
EMULATOR is a SW package that emulates the full
chain of the Trigger Chips and Boards. It works
offline and need as input the times recorded by
the TDCs. Emulator is not the CMS
simulation,it should reproduce exactly the
Trigger data. To compare with the expected
performance as shown in the Trigger TDR we
should compare with the full track reconstruction
from TDC data. However this first result is in
excellent agreement with what we expect.
27
CONCLUSIONs
The results of the tests performed in the
production site with Cosmic Rays of each Barrel
Muon Drift Chamber of the CMS experiment are very
good and confirms the 2000(cms note01-051) ,2001
(cms note03-07) and 2003 Test Beam results
Noise lt25 Hz/m Efficiency uniform 99
/ layer cell layer vs phi angle
vs theta angle Resolution 250m/cell
100m/SL Mean Time cell layer phi
angle theta angle Layer position
accuracy lt 110 m all Layers/SL SLs
F position accuracy lt 1mm
linear fit Trigger tests with cosmic
good
Cosmic rays are free, have no schedule ,
illuminate uniformly, are in all production sites.
28
help1
The Installation Task
The Barrel Muon system comprises 250 chambers in
7 flavors

• 60 MB1 3SL 2 RPC 2.0 x 2.54 m2 960kg
• 60 MB2 3SL 2 RPC 2.5 x 2.54 m2 1200kg
• 60 MB3 3SL 1 RPC 3.0 x 2.54 m2 1300kg
• 40 MB4 2SL 1 RPC 4.2 x 2.54 m2 1800kg
• 10 MB1 2SL 1 RPC
• 10 MB2 2SL 1 RPC
• 10 MB3 2SL 1 RPC

4
3
5
2
6
1
7
12
8

11
9
10
F SL
?SL
Honeycomb
MB4 (Torino) Have two Superlayers only
F SL
10 Sectors will be installed in SX5 gt 210
Chambers(310 RPCs). Sectors 1 and 7 are used for
the lowering fixture and will be installed in UX5
gt 40 Chambers(60 RPCs).
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Help cell
42 mm
the position of the s equipotential depends
on the cell geometry (i.e. on the strip width
and on the wire radius) Vw-Vs
determines the GAIN in the gas the request of
a gain of 105 determines the position of
the s equipotential to be 2.5 mm
from the wire
the presence of the grounded Al plates and beams
between S and C makes the position of the g
equipotential quite independent of
the Voltages of s and c Vc ( and Vs) must
generate in the region between c and g ( and
between g and s ) an E field between 1 and 2
KV/cm to saturate the drift
velocity
LHCC Comprehensive Review 10/2/01
CMS MUONS Drift Tubes and Alignment

fabrizio
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Help schedule
LNL 5/9/2003 96 SL 32
CH Aachen 15/8 102 SL 34
Madrid 10/9
120 SL 34 CH 100 ch out of 210
Chambers at ISR MB1 20 by
dec.03 29
MB2 28 38
MB3 25
30 Total
73
97 These figures can imply that all the
dressing will be done for all chambers at ISR
(to be agreed)
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Help BTI


a
a



Shift registers

b


a b T
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Help ISR
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Help TB2003 Traco CCB
BX Efficiency -2
HH HL LL
drop of correlated efficiency at large angles due
to geometrical cuts (single BTI 56o traco 42o)
Ho Hi Lo Li
15
DT Trigger Performance - Sara Vanini
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Help TB2000 BTI
BTI test in Magnetic Field (test beam 2000, CMS
note 2001/051)
Prob. of one/4 layers affected by delta 16,
more than one 4
B (TESLA) longitudinal component
CMS TN 051 2001
.31
H-trig 4/4 layers L-trig 3/4 layers
BTI n
BTI n1
B (TESLA) radial component
BTIs overlap