Technical Board Meeting Y'P' Viyogi, VECC, Kolkata

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Technical Board Meeting(Y.P. Viyogi, VECC,
Kolkata)
New results Detector at high particle
flux Results from cooling model tests Photon
counting algorithm, efficiency, purity, effect
of material Addendum to PMD TDR
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Particle flux on PMD
pp ArAr ArAr PbPb Rate 2.105 9.103 3.105
8.103 Nch/Event 100 2400 2400 14200 ------------
--------------------------------------------------
----------------------- TDR case (5.7 of total
particles on PMD, N? ? Nch) (ch ?) on
PMD 12 274 274 1620 FluxHz/cm2 24 25 822 130
------------------------------------------------
------------------------------------- Relocated
case (6.3 of total particles on PMD, N? ?
Nch) (ch ?) on PMD 13 302 302 1790 FluxHz/cm2
130 136 4530 716
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Behaviour at large flux using ?-source

• Study the detector anode current (integrated)
  with source
• as a function of time
• as a function of voltage
• Hypothesis If the ionization within the cells
  do not dissipate fast enough, the charges should
  accumulate, and slowly the anode current will
  rise.
• If there is lot of ionization and the
  detector is operated at a voltage much higher
  than normal operating value, anode current may
  show sudden jump or breakdown condition may
  occur.
• A 25 micro-Curie Sr-90 source used.

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Anode current vs. time
43 kHz/cm2
19 kHz/cm2
7 kHz/cm2
No source
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Anode current vs voltage
43 kHz/cm2
19 kHz/cm2
7 kHz/cm2
No source
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An Extreme Case
Flux 43 kHz/ cm2 Voltage -1600V
Summary of investigations with ?-source
Detector generally stable up to 1600V for
flux up to 43 kHz/cm2 No indication of charge
accumulation
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Cooling ¼ scale model tests
Mockup for heat load of PMD FEE boards height
same as PMD width ¼, 21 columns of FEE boards
(total in PMD 84 columns) (each column 24
boards) heat load 1watt per board of 64
channels Covered in polythene sheet 5cm away from
board surface. Cooled by chilled air from room
A/C units Sensors mounted around the whole model
to monitor temperature profile (47 sensors)
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Cooling model
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Cooling test results
Flow rate Input Temp Output Temp 0 ---- 60 39
l/s 21 30 39 l/s 9 17.5 72 l/s 17 24
A differential of 7 deg. is obtained easily. No
fine tuning of input temp or flow rate was done.
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Cooling Temperature profile
No cooling
Cooling, 72 l/s, 17C
Top hot
Top cool
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Photon counting algorithm - 1
Data or simulation a set of hits on preshower
and veto planes

• Clustering of hits
• Photon-hadron discrimination
• (vetoing, rejection of split clusters etc.)

Reconstruction
A set of clusters called gamma-like
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Photon counting algorithm -2
Gamma-like clusters (N1), in data or simulation
Simulation Photon track origin (N2)
Non-photon track origin, remaining split
clusters are contaminants
N No. of photon tracks coming from vertex
within the detector acceptance
Efficiency (e) N2 /N Purity (p) N2 /N1
In experiment, we have N1, we want to estimate
N. N N2 / e (N1 p) / e we need e,p from
simulation
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Modeling the ITS services
actual
dummy
Dummy 3X0
Dummy 1X0
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?-dependence of efficiency and purity
Efficiency
Purity
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Eff./Pur. Average values
Case Detector Eff. Pur. ----------------------
--------------------------------------------------
---------- Relocated PMD in air 57 (63) 70
(71) PMDfull ITS 46 (52) 63 (63) PMD
Dummy (3X0) 48 (53) 64 (63) PMD Dummy
(1X0) 54 (60) 65 (64) TDR PMD in
air 73 75 TDR PMDall detector 68 61 WA98
PMD 68 65
( ) Truncated acceptance of ? 2.3-3.1
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Eff./Pur. for lower multiplicities
PMD in air

• ?0 ?2.3-3.5 ? 2.3-3.1
• N? Eff. Pur. N? Eff. Pur.
• 8000 4500 57 70 3200 62 71
• 5000 3600 60 70 2500 66 70
• 1400 75 69 1000 79 69
• 1250 700 82 69 500 84 69

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Addendum to PMD TDR
Chapters

• Introduction
• Modified detector design
• Mechanical description
• Physics performance
• Integration, costs, time schedule

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1. Introduction
1.1 Need for relocation 1.2 New Location 1.3
Effect of relocation 1.3.1 Particle
density 1.3.2 Granularity 1.3.3 Particle
flux 1.4 Comparison of basic parameters
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2. Modifications in detector design
2.1 Prototype fabrication and tests 2.2 Results
for charged particle detection 2.2.1 Pulse
height spectra and operating parameters 2.2.2
Variation of efficiency within a
cell 2.2.3 Relative gains of cells 2.3 Preshower
results 2.4 Behaviour at high particle
flux 2.4.1 Prototype-3 using SPS
beam 2.4.2 Prototype-2 using radioactive soure
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3. Detector description
3.1 Mechanical design 3.1.1 Unit modules and
supermodules 3.1.2 Connection to front-end
electronics 3.1.3 Cooling 3.1.4 Suspension
mechanism and servicing 3.2 Electronics and
readout 3.2.1 MANAS chip 3.2.2 FEE
boards 3.2.3 Readout chain 3.2.4 CROCUS 3.2.5
Dead time
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4. Physics performance
4.1 Measurement of photon multiplicity 4.1.1
Simulation framework 4.1.2 Reconstruction 4.1.3
Effect of upstream material deflection of
tracks 4.1.4 Occupancy 4.1.5 Results on
efficiency and purity 4.2 Effect of relocation on
the physics potential of PMD 4.2.1 Transverse
electromagnetic energy 4.2.2 Azimuthal
anisotropy and flow 4.2.3 Fluctuations in
multiplicity and pseudo-rapidity
distributions 4.2.5 Charged neutral
fluctuation and DCC
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5. Integration, time schedule and costs
5.1 Integration and servicing 5.2 Cost and time
frame
Important milestones Job description Completion
date PPP tests Sept. 2003 PRR Nov.
2003 Unit module production July
2005 Supermodule production Sept. 2005 FEE
boards, CROCUS Dec. 2005 Mechanics, slow
control July 2005 Detector calibration Sept.
2006 Pre-installation at Point 2 Dec.
2006 Installation in L3, commissioning Feb. 2007