Post on 13-Jan-2016
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
1
The CMS Preshower DetectorOverview
CERNArmenia : Yerevan Physics Institute
Belarus : Minsk University
Greece : N.C.S.R. Demokritos U. of Ioannina
India :Bhabha Atomic Research Centre U. of Delhi
Russia : JINR Dubna
Taiwan : National Central University National Taiwan University
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
2
Crystal BarrelCrystal Endcaps
Preshower endcaps
The CMS Preshower DetectorOverview
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
3
Crystal Endcaps : Pseudorapidity 1.479 < η<3.0
138 Standard SuperCrystals (25 crystals) 14 Special SuperCrystals 3622 Crystals
The CMS Preshower DetectorThe ECAL Endcaps
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
4
The CMS Preshower DetectorFiducial Coverage
y
z
Barrel ECAL (EB)
Endca
p E
CA
L (E
E)
n=1.
479
n=3.0n=2.6
n=1.
653
The fiducial coverage of SE extends from 1.653<η<2.6
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
5
The CMS Preshower DetectorPhysics Goals
1
0.1
0.3
0.01
0.03
0.001
0.003
50 100
130GeV
150 200 250
cc
gg
Z
MH (GeV)
mW 2mZ
bb
BR( for mH<150
GeV/c2
π0 ‘s from jets fake a photon from Higgs decayπ0γγ : γγ separation in barrel : ~ cm (possible using crystal information only) γγ separation in endcaps : ~ mm (quite poor using crystal info)
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
6
The CMS Preshower DetectorDesign Criteria
Abso
rber
shower profile
Abso
rber
Transverse
shower profile
Transverse
The Preshower acts as a sampling calorimeter:Lead absorbers : initiate EM showersSilicon sensors : act as energy sampling devices
The Absorber : 3X0(η = 1.7) 95% conv. prob.
The silicon sensors :• Fabrication on 4” wafers• Large Area : 63 mm x 63 mm• Thickness : 320 μm• Number of Strips : 32• Strip Capacitance ~ 42pF• Occupancy ~ 1%
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
7
The CMS Preshower DetectorDetailed Structure
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
8
The CMS Preshower DetectorSensor Overlap
PACE
Silicon sensor
Ceramicsubstrate
Aluminium tile
Absorber
Motherboard
Polyimideumbilical
Cooling screen
Motherboard
• 1-D sensor overlapping • 2mm wide dead space in one direction• tile + ceramic + sensor+PACE micromodule • 4288 identical micromodules in the complete SE (both endcaps)
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
9
The CMS Preshower DetectorMicromodules
1000 micromodules to be made in Greece by
Demokritos & Un. of Ioannina
Silicon Detector
CeramicSupport
externalcomponents
PACE
Flat cable
Hybrid
BiasVoltage
AluminiumHolder
Real micromoduleused in beam tests'98, '99 & '00
Micro-module
Schematic
Real
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
10
The CMS Preshower DetectorLadders
Services
Al frame
Al frame
Digital electronics boardPACE
Detector
Base plate
LadderSch
emat
ic
Real
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
11
The CMS Preshower DetectorLayout
Each end cap : 4.5m2
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
12
The CMS Preshower DetectorSilicon Sensors Design
1780 μm
1800 μm
1900 μm
...
58900 (1900 x31)μm
900
μm
1945 μm
100
μm
325
μm
63000 μm
AlSiO2
p+n type Si, 300 μmn+
...
1150 μm
100
μm
100
μm
150
μm
375
μm
1780 μm
1800 μm
1900 μm
...
58900 (1900 x31)μm
900
μm
1945 μm
100
μm
325
μm
63000 μm
AlSiO2
p+n type Si, 300 μmn+
...
1150 μm
100
μm
100
μm
150
μm
375
μm
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
13
The CMS Preshower DetectorSilicon Sensors Mask
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
14
The CMS Preshower DetectorSilicon Sensors Parameters
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
15
The CMS Preshower DetectorElectronics
PACE is the compinationOf 2 chips:Delta and PACE_AM
Delta front-end +Programmable biasingAnd calibration
PACE_AM160 column, 32 deep FIFO.Programmable biasing, mux
40MHz clock
New Design in submicron tecnology (will be delivered for testing in May 2003)
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
16
The CMS Preshower DetectorElectronics (Submicron Technology)
Delta3.. area = 17mm2, [Delta 2 = 21mm2]
PACEAM3.. area = 30mm2,
[PACEAM2 = 60mm2]
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
17
LAN
GPIB
LabVIEWHost
HP 4192ACapacitance Meter
Keithley 6517HV Source &Current Meter
32 channelrelay switch board
IV & CV Measurement SetupIV & CV Measurement Setup
Barcode ReaderCRISTAL
Database Host
Serial cables
LANLAN
GPIBGPIB
LabVIEWHost
HP 4192ACapacitance Meter
HP 4192ACapacitance Meter
Keithley 6517HV Source &Current Meter
Keithley 6517HV Source &Current Meter
32 channelrelay switch board
32 channelrelay switch board
IV & CV Measurement SetupIV & CV Measurement Setup
Barcode ReaderBarcode ReaderCRISTAL
Database Host
Serial cablesSerial cables
The CMS Preshower DetectorSilicon sensors measurement setup
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
18
The CMS Preshower DetectorSilicon sensors characteristics(1)
0.00E+00
2.00E-11
4.00E-11
6.00E-11
8.00E-11
1.00E-10
1.20E-10
1.40E-10
1.60E-10
0.00E+00 5.00E+01 1.00E+02 1.50E+02 2.00E+02 2.50E+02
Bias Voltage (in volts)
Str
ip t
o B
ackp
lan
e C
apac
itan
ce (
in f
arad
s)34 Sensors manufactured by Demokritos (Institure of Microelectronics-IMEL) while the masks were designed by INP
Half of them have been given to University Of Ioannina
At this point in Demokritos we have 87 sensors within specifications (17 from IMEL and 70 from ELMA-Russia)
0,00E+00
1,00E-09
2,00E-09
3,00E-09
4,00E-09
5,00E-09
6,00E-09
7,00E-09
8,00E-09
9,00E-09
1,00E-08
0 100 200 300 400 500 600
Bias Voltage (in volts)L
eaka
ge
Cu
rren
t (i
n a
mp
ers)
C-V
I-V
Final goal to deliver 1000 sensors to the CMS collaboration
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
19
Depletion voltage for each strip of the 34 sensors (Volts)
The CMS Preshower DetectorSilicon sensors characteristics(2)
Breakdown voltage for each strip of the 34 sensors (Volts)
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
20
The CMS Preshower DetectorSilicon sensors characteristics(2)
Breakdown voltage for each strip of the 34 sensors
Leakage Current at Depletion voltage for each strip of the 34 sensors (Ampers)
Leakage Current at 300V for each strip of the 34 sensors
(Ampers)
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
21
C.R.I.S.T.A.L. Local Center Software Architecture
UserApplications
ProductManagers
LocalCenter
Manager
DataDuplication
Manager
InstrumentAgents
DigitalControlPanels
ConfigurationDatabase
ProductionDatabase
MainDatabase
Objectivity V5.2
VirtualInstruments
Labview V5.1
Orbix V3.0.1
CORBA
PhysicalInstruments Central
Repository
Implemented in Windows 2000
The CMS Preshower DetectorSilicon sensors
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
22
The CMS Preshower DetectorExpected response for single γ
CMSPreshower
T
Transv erse shower
prof ile seen in the silicon strips
of the preshower
SE
EE
A single 30 GeV pT (η = 1.7) photon on the SE and EE
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
23
The CMS Preshower DetectorExpected response for π0
CMSPreshower
Transverse shower
profile seen in the silicon strips
of the preshower
SE
EE
Two closely spaced photons (~1 cm) from the decay of a 30 GeV pT π0 (η = 1.7)
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
24
The CMS Preshower DetectorPhoton (coming from π0) separation in Preshower
photon
Unfortunately these are not ‘typical’ events
PreShower strip = 6 cm x 2 mm
0
=1.7
=2.4
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
25
The CMS Preshower Detectorπ0/γ Preshower cluster energy distribution
Indication of separation power: Variation of Width with Et
Et=20, =1.7
Et=50, =1.7
0/ 0/
Clearly lose separation power at higher Et (even worst at higher η)
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
26
The CMS Preshower Detectorπ0 rejection algorithm
particle
Layer1 (x) Layer2 (y)
Preshower information: Energy (fraction) in 11 strips
•Extrapolate a straight line from ECAL cluster barycenter to point (0,0,0)
• Find the intersection of this line with the two Preshower planes
•The strip closest to the intersection point is defined as the ‘Central Strip’
Central strip definition:
around a ‘Central’ strip
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
27
The CMS Preshower DetectorNeural Network π0 rejection algorithm
Use Neural Network
(Feed-Forward Back-Propagation)
23 input variables: 22 PreShower + 1 ECAL crystals
For each strip i in layer 1: Ei / i=1..11 Ei
For each strip i in layer 2: Ei / i=1..11 Ei
Crystal information: S1/S25
‘Central’ strip: extrapolation from crystals
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
28
The CMS Preshower DetectorNeural Network output
Performance: Look for 0-rejection @ 90% -efficiency
Et=20, =1.7
Et=60, =2.4
00
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
29
The CMS Preshower Detectorπ0 rejection vs Et and η
CMSIM : Detector simulation based on GEANT
ORCA : Detector Reconstruction
ATHENS HEP2003 A.Kyriakis (Preshower INP Demokritos group)
30
The CMS Preshower DetectorConclusions
•Demokritos is able to manufacture high quality Silicon Sensors to be used in the CMS-Preshower project
•A part of the sensors will be manufactured in Demokritos and the rest will be bought by ELMA- Russia and Hammamastu
•Neural Network techniques gave good results in π0 rejection and will be soon implemented in the official CMS reconstruction Software