Post on 31-Dec-2015
description
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
The CBM Time-of Flight wall
Outline:• Motivation• CBM-ToF Requirements• Conceptional Design• Pad MRPCs• Wide strip MRPCs• Summary
Ingo Deppner for the CBM-TOF Group
Physikalische Institut Uni. Heidelberg
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Motivation
CBM Physics topics Deconfinement / phase transition at high ρB
QCD critical endpoint The equation-of-state at high ρB
chiral symmetry restoration at high ρB
Observables excitation function and flow of strangeness and charm collective flow of hadrons particle production at threshold energies excitation function of event-by-event fluctuations excitation function of low-mass lepton pairs in-medium modifications of hadrons (ρ,ω,φ → e+e-(µ+µ-), D)
In order to measure all these observables with an high accuracy, we need a good particle identification
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Particle ID
Hadrons: STS + TRD + TOF
Electrons: STS + MVD + TRD + TOF + ECAL
Muons: STS + MUCH + TOF
Open Charm: STS + MVD
Hyperons: STS
Photons: ECAL
Motivation
Kaon acceptance depends critically on TOF resolution
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
CBM-ToF Requirements
full system time resolution T ~ 80 ps
Efficiency > 95 %
Rate capability < 20 kHz/cm2
Acceptable cross-talk and charge-sharing.
Low power electronics (~75.000 channels).
Pile-up < 5%
Occupancy < 5 % (for Au-Au(central) at E=25 GeV/A)
Sufficient space resolution
Timing RPCs are one of the possibilities to fulfill the CBM-ToF requirements
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
CBM-ToF Requirements
Timing RPC with:
active area: A = 120 m2
counter time resolution: T ~ 50 ps
rate capability: R ~ 0.5 – 20 kHz/cm2
granularity: A ~ 6 – 100 cm2
operation mode: free running
Which is the best solution to adjust the granularity – pad or strip?
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Conceptional Design
In order to accommodate the different granularities as a function of the polar angle, four different regions were defined:
Pad/narrow strip region: 2.5 x 2,5 cm2 (rate: 20 - 8 kHz/cm2 , area: 12 m2 , #SM: 8) Strip/narrow strip region: 25 x 1 cm2 (rate: 8 - 3.5 kHz/cm2 , area: 24 m2 , #SM: 16) Strip region: 50 x 1 cm2 (rate: 3.5 – 1.5 kHz/cm2, area: 36 m2 , #SM: 24) Strip region: 50 x 1 cm2 (rate: 1.5 – 0.5 kHz/cm2 , area: 48 m2 , #SM: 32)
main tasks that have to be solved are rate capability and granularity
Maximal pad size? depends on required timing resolution
for a quadratic pad:
x
pad xmax = T · v · 12xmax = 3,5 cm
T : timing resolution (T ~ 50ps)v : signal velocity (v = 20 cm/ns)
a = xmax / 2 = 2,5 cm
a
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Conceptional Design
1 SM with 120 pad RPC
active area is not overlaped
active area: 5 x 25 cm2
read out: single ended
channels: 120 x 20 = 2400 / SM
glass: low resistive / ceramics
1 SM with 20 strip RPC
active area slightly overlaped
active area: 32 x 25 cm2
read out: both sides
channels: 20 x 32 x 2 = 1280 / SM
glass: low resistive
1 SM with 10 strip RPC
active area slightly overlaped
active area: 32 x 50 cm2
read out: both sides
channels: 10 x 32 x 2 = 640 / SM
glass: low resistive
1 SM with 10 strip RPC
active area slightly overlaped
active area: 32 x 50 cm2
read out: both sides
channels: 10 x 32 x 2 = 640 / SM
glass: float (+ warming up)
In total ~ 75000 channels
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
CBM-TOF Groups
Pad MRPC with semi conductive glass
Pad RPC with ultrathin glass
Narrow strip MRPC
Ceramic MRPC
- Tsinghua
- IHEP
- NIPNE
- FZD
Wide strip MRPC with semi conductive glass
Wide strip MRPC with semi float glass
- Tsinghua
- GSI, USTC, UHD
Scintillator with MAPD readout - INR, ITEP
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Pad MRPC
Pad MRPC developed at Tsinghua university, China
13 cm
Pad:2 cm x 2 cm
First preliminary results
Glass type: common / silicateHV electrode: colloidal graphiteNumber of gaps: 10Gap width: 0.25mmGlass thickness: 0.7mmGas mixture: Freon/iso-butane/SF6 92%/3%/5%
Pad structure of the pickup electrode
Talk by Jingbo Wang
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Ceramic MRPC
Talk by Lothar Naumann
Ceramic MRPC developed at Forschungszentrum Dresden Rossendorf
Number of gaps: 4Gap width: 0.3 mmCeramic thickness: 2 mmGas mixture: Freon/iso-butane/SF6 85%/10%/5%
efficiency
time resolution
300 kHz/cm2
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Ultrathin glass Pad RPC
Pad „mini“-RPC developed at Institute for High Energy Physics, Protvino
Ammosov , V. Gapienko, A. Semak, Yu. Sviridov, V. Zaets, E. Usenko
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Narrow strip MRPC developed at NIPNE, Bucharest
narrow strip MRPC
cluster size
time resolution
efficiencyTalk by Mariana Petris
BUCT1 – 9.5 kV
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Wide Strip RPC
Wide strip MRPC with common and low resistive glass developed at Tsinghua university, China
~95 %T~70-80 ps
~95 %T~70-80 ps
Talk by Jingbo Wang
Talk by Diego Gonzalez-Diaz
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Wide Strip RPC
Strip MRPC developed at UST China
Glass type: float HV electrode: Licron spray (40 M/cm2)Number of gaps: 10Gap width: 0.25 mmGlass thickness: 0.7 mmGas mixture: Freon/iso-butane/SF6 92%/3%/5%
Cross talk at neighbar strip: ~ 3%
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Wide Strip RPC
active area: 28 x 16.5 cmstrips: 16strip / gap: 7 / 3 mmglass thickness: 0.55 mm floatnumber of gaps: 8gap width: 220 mgas: Reclin/SF6/iso-But 85/10/5pickup electrode
Fully differential Strip MRPC developed at Physikalische Institut Uni. Heidelberg
Imp. ~ 80
Counter is designed for an impedance of 100 strip size ~ avalanche size (FOPI)
reflectometer measurements
total efficiency ~ 95%
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Theory and simulation
probability of pure cross-talk: 1-3%
[kHz/cm2]
Diego Gonzalez-Diaz, GSI
HD counter
from DC-model
A,B: constantq: charge: glass resistivityd: glass thickness: flux
USTC counter
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Summary
Time line
Demonstrators end 2009 Electronics chain end 2009 Demonstrators with ‘final’ electronics end 2010 TDR end 2011 Full size prototypes end 2012 Construction 2012-2014 Integration 2014-2015
RPC type res. material efficiency time resolution
rate capability
cross talk
Pad MRPC sem. glass 95 % 75 ps not meas. not meas.
Ceramic MRPC ceramic 95 % 110 – 140 ps 500 kHz/cm2 not meas.
Pad „mini“-RPC ultrathin glass 75 % (1 Gap) 75 – 100 ps 1,5 kHz/cm2 no
narrow strip RPC float glass 85 % 50 ps not meas. < 5 %
Wide Strip (Beijing) sem. glass 95 % 75 ps 20 kHz/cm2 10 – 20 %
Wide Strip (USTC) float glass 95 % 65 ps not meas. 1- 3 %
Wide Strip (UHD) float glass 95 % 75 ps not meas. 1- 3 %
rate capability of float glass can be improcved by warming up (~factor 10/26K)
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
thank you for your attention
Contributing institutions:Tsinghua Beijing,NIPNE Bucharest,LIP Coimbra,GSI Darmstadt,USTC Hefei,PI Heidelberg,KIP Heidelberg,
INR Moscow,ITEP Moscow,IHEP Protvino,FZD Rossendorf,KU Seoul,RBI Zagreb.
RPC 2010 Workshop, GSI, 09 - 12.02.2010
Ingo Deppner
Wide Strip RPC
pickup electrode
Imp. ~ 80
reflectometer measurements
HV electrode
licron layer
Cu-strip
surface resistance 100 M/cm2
glass substrate
trigger area