Transcript Document

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.
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Barrel muon system
5 wheels
30o sectors with 4 stations
250 DT chambers
2.0x2.5 m2 (MB1)
4.0x2.5 m2 (MB4)
~2*105 channels
480 RPC chambers
MB4
MB3
MB2
MB1
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
CMS Drift Tube Chambers
“SuperLayer” (SL 2)
(coord. in bending plane)
SL  (non-bending plane)
honeycomb panel
SL 1
Within one SL 4 layers staggered by half a cell to solve L/R ambiguity
tA
A
B
C
D
42mm
S
13mm
W
tB
tC
C
tD
g
s
a
b
b/a ~ .65
continuous lines represent electrodes
dotted lines represent equipotential surfaces
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Muon system specifications
Muon identification
(after >10  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
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Laboratori Nazionali di Legnaro (padova): DT chambers
construction
glue for I-beam
LNL
HV & LV boards
A.T. Meneguzzo
Padova University & INFN Padova
Final chamber
ICATPP 2003
Como 6-10 october, 2003
Barrel Muon : DT chamber requirements
•drift time vs position linearity in the cell
First Level Trigger
(Mean time technique on staggered layers)
•
Bunch crossing identification
•
Track segment reconstruction
•100mm precision on wire position
within a SL
• <1mm between  SL
Pt cut : sharp efficiency curve
Muon track parameter
•Resolution of 250mm/cell
-
muon ID coverage up to IhI=1.1
• Max Efficiency
-
momentum & charge assignement
•Minimum Noise level
we want to
measure for
each chamber
Noise
Efficiency
Resolution
Wire and Layer position accuracy
SL F position accuracy
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Chambers and Trigger set up at LNL
Chamber under test
Chamber under trigger test
Local Trigger CCB
Cosmic Rays : trigger set-up
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
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
Analisys Off-line:
-track reconstruction
N.Toniolo LNL
-trigger emulator
MONITOR :on line analysis
-ntuples production with
–occupancy
raw data and tracks
information
-noise
-efficiency
ORCA framework
P.Ronchese et al., Pd
-MT
-Event Display
ORCA framework
Sara.Vanini et al., PD
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Cell and drift time distribution checks
1800 V
3600V
Strips
good
-1200 V
Drift time
bad but it
can be
recovered
Bad cathod
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Noise
Noise of the channels
in all layers of a chamber
of all chambers
channel
channel
20 Hz/m
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Noise vs Hv and noise vs Th
Noise vs HV on the wire
A.T. Meneguzzo
Padova University & INFN Padova
Noise vs FrontEnd Threshold
ICATPP 2003
Como 6-10 october, 2003
Efficiency
cell efficiency in the layer
efficiency inside the cell
geometrical inefficiency
I-beam
1.2/42= 3% for normal tracks
wire
1.00
0.96
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Efficiency :angle & all chambers
Dead
angle= 90
98%
99%
Mean SL Efficiency
for the first 12 chambers
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
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
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
fit with ‘time’
Mean time
y
t
t3
4
t2
t1
semicolumn
2
MT
234 
 t3  Tmax
drift
t
2

t
4
V  d / Tmax
2
123
MT 
 t2  Tmax
t1  t3
d staggering
21000/ 380ns
Vdrift=55mm/ns
s= 1.6ns Wire position accuracy~70mm
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
Resolution=250mm
Resolution smt=sqrt((s2-s trig_pm2) =3/2sl2
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
MT: Layer displacement
Example: layer 4 displaced of dx
MT
234L
Dt
t4
t3 4
MT234R
Dt = ( MT234R- MT234L) using the mean
value of all MT234 ->good accuracy
Layer 4 displacement -> Dx =Dt * vdrift
t2
t1
MT123L  MT123R
2

 t3  Tmax
t 2  t4
2

 t3  Tmax
t 2  t4
2d staggering

 t2  Tmax
t 1  t3
Mean 378 ns
Mean 383 ns
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
MT :
signal wire propagation
Measurement of the signal propagation along
the wire
vsignal=0.244 m/ns
FEside
vdrift=21/378=0.55mm/ns
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
MT summary
Resolution in the cell
Drift velocity in the cell
Accuracy on staggering and
wire position
s1.7 ns 
66 mm
For all chambers
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
MT vs angle
The apparent drift velocity grows with y angle;it is constant for 
F angle
A.T. Meneguzzo
Padova University & INFN Padova
 angle
ICATPP 2003
Como 6-10 october, 2003
F Super Layers alignment
All 4 point tracks, || < 20o
62215 mm
build 4 point segment
in each single SL
x2
MB3_12
Extrapolate to the
middle plane of the chamber
x1
A.T. Meneguzzo
Padova University & INFN Padova
-3.80.1 mrad
ICATPP 2003
Como corrections
6-10 october, 2003
before alignment
Layer alignement : 7 point fit residuals
<>=-1755 mm
SL 1
SL 2
<>=205 mm
MB3_12
<>=395 mm
<>=655 mm
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
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
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
after alignment corrections
Como 6-10 october, 2003
DT Chamber performance in Test Beam
MB2 :TEST BEAM 2001 Resolution and
Plateau knee
Hit rate in SL1 is
3.5 (1.7 for SL 2)
larger than the
worst case at LHC
(shown SL1)
192
micron
Drift cell effic.&resolution
With increasing Background
A.T. Meneguzzo
Padova University & INFN Padova
CMS Note 2003/007
192
micron
ICATPP 2003
Como 6-10 october, 2003
DT Chambers: 1st Level Trigger
SL2 BTI outer
SL1 BTI inner
H 4 points track
L 3 points track
BTI outer
TRACO
TSS/TSM
H
**
*
*
HH
*
BTI inner * H
*
*
A.T. Meneguzzo
Padova University & INFN Padova
L
*
H
*
*
HL (LH)
** H
*
*
Ho
*
*
*
*
ICATPP 2003
N
*
*
*
*
*
N *
*
Hi
*
*
*
*
H
Como 6-10 october, 2003
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 ->correlated trigger
Bunch crossing identification
Angle
trigger
-450
450
Angle track
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
BunchedTB
TB2003
2003DTchamberTriggerPreliminary
DTchamberTriggerPreliminary
Bunched
trig. at 14bx
efficiency =
total # of events
Event= scintillator + 2 hits in
beam region
tracks hitting 2 I-beams
“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.
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
~ 98-99 %
efficiency up to 350
Como 6-10 october, 2003
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
Efficiency uniform
cell
layer
vs phi angle
vs theta angle
Resolution
Mean Time:
cell
layer
phi angle
theta angle
Layer position accuracy
SLs F position accuracy
linear fit
Trigger tests with cosmic
<25 Hz/m
99% / layer
~ 250m/cell 100m/SL
< 110 m all Layers/SL
< 1mm
good
Cosmic rays are free, have no schedule , illuminate uniformly, are in all production sites.
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
The Installation Task
help1
The Barrel Muon system comprises
250 chambers in 7 flavors:
5
4
60
60
60
40
10
10
10
3
2
1
6
7
8
9
10
12
11
MB1
MB2
MB3
MB4
MB1
MB2
MB3
3SL
3SL
3SL
2SL
2SL
2SL
2SL
2 RPC ~2.0 x 2.54 m2 960kg
2 RPC ~2.5 x 2.54 m2 1200kg
1 RPC ~3.0 x 2.54 m2 1300kg
1 RPC ~4.2 x 2.54 m2 1800kg
1 RPC
1 RPC
1 RPC
F SL
SL
MB4 (Torino)
Have two Superlayers only
Honeycomb
F SL
10 Sectors will be installed in SX5 => 210 Chambers(310 RPCs).
Sectors 1 and 7 are used for the lowering fixture and will be
installed in UX5 => 40 Chambers(60 RPCs).
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
42 mm
Help cell
C
S
g 13mm
s
continuous lines represent electrodes
a
W
b
b/a ~ .65
dotted lines represent equipotential surfaces
the position of the s equipotential depends
on the cell geometry (i.e. on the strip width
and on the wire radius)
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
Vw-Vs determines the GAIN in the gas :
the request of a gain of ~ 10^5 determines
the position of the s equipotential to be
~ 2.5 mm from the wire
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
A.T. Meneguzzo
LHCC
Comprehensive
Padova
UniversityReview
& INFN10/2/01
Padova
ICATPP 2003
CMS MUONS: Drift Tubes and Alignment
Como 6-10 october, 2003
fabrizio
Help schedule
LNL 5/9/2003
Aachen 15/8
Madrid 10/9
96 SL
102 SL
120 SL
32 CH
34
34 CH
100 ch out of 210
Chambers at ISR
Total
MB1
MB2
MB3
20
28
25
by dec.03
73
29
38
30
97
These figures can imply that all the dressing will be done for all
chambers at ISR (to be agreed)
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Help BTI
*
aa *
*
*
*
Shift registers
b
*
*
*
a +b = T
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
Help ISR
A.T. Meneguzzo
Padova University & INFN Padova
ICATPP 2003
Como 6-10 october, 2003
BX Efficiency -2
Help TB2003 Traco CCB
HH HL LL
drop of correlated
efficiency at large
angles due to
geometrical cuts
(single BTI 56o
traco 42o)
Ho Hi Lo Li
DT Trigger Performance - Sara Vanini
15
BTI test in Magnetic Field (test beam 2000, CMS note 2001/051)
Help TB2000 BTI
Prob. of one/4 layers affected by delta 16%, more than one 4%
B (TESLA) longitudinal component
CMS TN 051 2001
BW
Bn
.05
.1
.16
.21
.19
.38
.56
.77
1.15
.31
H-trig = 4/4 layers
L-trig = 3/4 layers
BTI n
BTI n+1
A.T.
B Meneguzzo
(TESLA) radial component
Padova University & INFN Padova
.26
.96
ICATPP 2003
BTIs overlap
Como 6-10 october, 2003