ITEP participation

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CBM Russia meeting at ITEP, Nov 5th, 2004
ITEP participation to the CBM
TOF project
ITEP ALICE - TOF group
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ITEP background in gaseous TOF technology
1991 - ITEP Proposal for HI Proto Collab. then
ALICE to develop new technology of avalanche
gaseous detectors with planar electrodes for high
precision large area TOF
ITEP since 1991 key participant of the ALICE
PID/TOF project based on this technology
initially PPC, then RPC (DRPC, GRPC) for
sparks suppression, for construction MRPC -
all in the avalanche mode
ITEP - key participant in the discovery of new
TOF technology 50 psec resolution for MIP in
98

• ITEP now deeply involved in the ALICE TOF
  construction
• technology of the TOF strips assembly
• different types of the equipment/tooling needed
  for the assembly
• TOF strips and modules tests with beam and
  cosmic
• ALICE TOF Cosmic Test Facility at CERN
  
• ( in part. muon trigger system)

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ALICE TOF ToolingTest assembly of a TOF strip
involving new ITEP equipment
ITEP
A new ITEP device for vacuum handling of a 1.2
m-long TOF strip elements (containing PCBs and
thin glass plates)
ITEP specialists have just positioneda thin
glass plate on a PCB surfaceby means of the
vacuum handler
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ALICE TOF ToolingTest assembly of a TOF strip
involving new ITEP equipment
ITEP
TOF group members, discussing the technology of
the TOF strips assembly
A device for film gluingand a special table for
precision fixation of the strip elements
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ALICE TOF Tooling
ITEP
ITEP technicians, working on the technology of
the TOF strips assembly
Different types of devices to be used in uniform
covering of the TOF strip glass plates with
insulating films
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Close ITEP plans on the CBM TOF simulations
RD

• Optimization of the structure of TOF systems
• Influence of the time resolution to physics
• Efficiency, matching, contamination
• PID performance

• 2004 - newcomer
• Simulations of TOF performance
• Tests of RPC with the Russian low-resistivity
  glass at ITEP PS
• Data analysis
• 2005
• More simulations of TOF performance
• Enhanced TOF contribution to physics
• Further RD on TOF by RPC
• More RD

• Tests of glass RPC in laboratory and by beam
• Optimization of the detector design
• Optimization of FEE, other electronics

Surface resistivity instead of volume
- for instance - ITEP DRPC (Dielectric
Resistive Plate Chamber)
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TOF occupancy

• 1325 tracks cross TOF 433(33) primaries
  892(67) secondaries
• Composition of secon. 62 e, 16 p, 13 p, 9
  µ
• Origin of secondaries 4 from ECAL range, 37 -
  TOF, 12 - TRD3, 9 - TRD2, 7 - TRD1, 6
  -vertex
• Max. occupancy 0.45 prim. tracks, 0.65 secon.
  tracks per dm2 at beam pipe
• With 10 cm2 cell size max. occupancy 11

e-
e
p
p
?
TOF
TRD3
TRD2
ECAL
TRD1
02.06.2004
ITEP meeting
S.Kiselev ITEP 10
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TOF occupancy
02.06.2004
ITEP meeting
S.Kiselev ITEP 12
9
TOF RPC at the ALICE conditions
Glass resistance R 1013-12 Om cm, rate limit -
less 1kHz/cm2
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CBM TOF up to 150 m2, up to 150 K
Chan.
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RPC TOF rate capability
ALICE - 50-100 Hz/cm2 CBM - up to
50 kHZ/cm2 ! x 1000 times !
HADES test normal glass 1012 Om cm
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High-Rate Low-Resistive-Glass RPC for TOF
Measurements

• A. Akindinov ITEP (Moscow) for collaboration
• IHEP (Protvino) INR (Moscow) ITEP (Moscow)

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Glass Resistivity

• Glass by INR
• phosphate
• low-resistive
• electron type of conductivity
• produced in Moscow
• plates thickness 2 mm
• plates cut and polished

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• RPC by IHEP
• gaps 4 ? 0.3 mm
• plate size 50 ? 55 mm2
• readout pad 40 ? 40 mm2
• HARP type
• spacers fishing lines Ø 0.3 mm
• tight aluminum gas box

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• Beam tests
• 10 GeV ITEP proton synchrotron
• protons, p 1.7 GeV/c
• up to 0.5?106 particles/spill
• spill duration 300 ms
• beam spot 5 ? 5 cm2
• trigger 6-fold coincidence of scintillator
  counters MWPC tracking
• two TOF systems (5m base and 13 m base)
  Cherenkov detector

• Front-End Electronics
• single-channel card with discrete surface
  mounted elements
• put outside the gas box
• based on MAX3760 amplifier
• gain 2.5 V/pC
• rise-time 1.4 ns
• linearity up to 100 fC
• noise 1200 e- 300 e-/pF at the input
• threshold 10 fC
• snoise lt 20 ps

• Beam test facility
• start system timing resolution 70 ps (50 ps
  for start signal)
• trigger size at the RPC plane 1.2 ? 1.2 cm2
• studied occupancies 2.25, 4.5, 9.0, 18.0
  kHz/cm2
• statistics 105 events/point

Gas supply 85 tetrafluorethane 10 SF6 5
i-C4H10 5 l/h gas box volume 1 l
Data acquisition and analysis TDC LeCroy 2228
ADC LeCroy 2249 offline analysis with polynomial
T-A correction
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TOF resolution
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Main RD direction to build functional detector
with a glass with enough low resistivity.!
Bulk or Volume resistivity
Special low resistivity glass
well known problem since RD on Pestov
Another way surface resistivity
Example - DRPC invented by ITEP in 1998
DRPC (Dielectric-Resistive Plate Chamber) In
reality the very first example of novel TOF
technology 80 psec in
1998
Patent of Russia ? 2148283,
1998 Preprints ITEP 45-98, 1998
20-99, 1999
46-00, 2000 13-02,
2002 NIM A494, pp 474-479, 2002
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ITEP DRPC as a very high rate TOF
detector . ?
4 x 0.3 mm gaps ceramic SiC electr.