The CBM Time-of Flight wall

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RPC 2010 Worksho p, 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

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The CBM Time-of Flight wall. Ingo Deppner for the CBM-TOF Group Physikalische Institut Uni. Heidelberg. Outline: Motivation CBM-ToF Requirements Conceptional Design Pad MRPCs Wide strip MRPCs Summary. Motivation. CBM Physics topics Deconfinement / phase transition at high ρ B - PowerPoint PPT Presentation

Transcript of The CBM Time-of Flight wall

Page 1: The  CBM  Time-of Flight wall

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

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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

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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

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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

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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?

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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

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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

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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

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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

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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

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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

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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

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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

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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%

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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%

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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

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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)

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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.

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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