MRPC R&D and production

Yongjie Sun

Center of Particle Physics and Technology, USTC

2Jun.7, 2010

Index

Introduction R&D on MRPC

STAR TOF STAR MTD CBM TOF BES ETOF upgrade

Summary

3Jun.7, 2010

Introduction

MRPC (Multi-gap Resistive Plate Chamber) is a major new detector technology first developed by the ALICE experiment. The concept first published on Nucl. Instr.& Meth. A374 (1996) 132 by M.C.S.Williams et al.

Advantages:

Time resolutionHigh efficiencyLow costArbitrary readout shape

Good candidate for large area

Time-Of-Flight system !

MRPC

4Jun.7, 2010

Early R&D (2000-2002)

beam test at PS-T10, CERN ： efficiency >95% （ 5 gas gaps ） >97% （ 6 gas gaps ）

~ 99% （ double stack 2 5 gas gaps ） time resolution ~70ps （ 5 gas gaps ） ~60ps （ 6 gas gaps ）

~50ps （ double stack 2 5 gas gaps ）

M.Shao, L.J.Ruan, H.F.Chen et al.,

NIM A492(2002)344-350

MRPCs of different structures

60

working gas mixture: F134A(90%) ＋ iso- C4H10 (5%) ＋SF6(5%)

5Jun.7, 2010

STAR Upgrade -PID

TPC- tracking

MRPC TOF (TOFr) – stop time measurement

VPD - start time measurement

Particle momentum

dE/dx

~8% resolution

/K separation to ~0.6GeV/c

k/p separation to ~1.0GeV/c

Aim at 100ps time resolution TOF system

/K separation to ~1.6GeV/c & k/p separation to ~3.0GeV/c

6Jun.7, 2010

MRPC strip size ：3.15cm×6.30c

m

Module size ： 21.2×9.4×1.79 cm3

Gas gap ： 6×0.22mm

In 200 GeV central Au+Au:

Time resolution <100ps Efficiency 90%High granularity Rate >200Hz/cm2

MRPC Structure for STAR/TOF

7Jun.7, 2010

TOFr Tray Configuration

Total: Area: 64 m2

3840 MRPC modules ~23,000 channels

Tray: 6 in azimuth 1 in pseudo-

rapidity radius ~ 2.2 m

8Jun.7, 2010

Completed Prototype 28 module MRPC TOF Tray installed in STAR Oct. ‘ 02 in

place of existing central trigger barrel tray

NeighborCTB Tray

EMCRails

FEE

STAR-TOF prototypesTOFr Tray (1/120 coverage of Barrel STAR)

85 ps, 2 meter path

28MRPC, 24 made at USTC

9Jun.7, 2010

MRPC Mass Production After STAR Construction Readiness Review in April

2006, MRPC mass Production in China started. University of Sci. & Tech. of China (USTC) will produce 1210

MRPCs

1/2 3/4 5/6 7/8 11/129/10 1/2 3/4 5/6 7/8 11/129/10 1/2 3/4 5/6 7/8

2006 2007 2008

Prod. Start

40 MRPCs

+192 MRPCs

+326 MRPCs

+326 MRPCs

+326 MRPCs

10Jun.7, 2010

100 m2 clean room ( cleanness class 100K ): Temperature ： 25o C Humidity ： <40% 4 assembly desk ( cleanness class 100 )

MRPC Mass production

11Jun.7, 2010

MRPC mass production

12Jun.7, 2010

Mass Production QA/QC

QA/QC on all materials,

production procedure, and

produced MRPC modules

13Jun.7, 2010

QA of materials

glass PCB

honeycomb supporter

14Jun.7, 2010

QC setup – cosmic ray telescope

QC capability: 8 MRPCs / Day

15Jun.7, 2010

Monthly output

2006

Month Output

2007

Month Output Month Output

Jun. 12 Jan. 58 Jul. 120

Jul. 64 Feb. 24 Aug. 120

Sep. 55 Mar. 83 Sep. 119

Oct. 35 Apr. 80 Oct. 121

Nov. 42 May. 126 Nov. 120

Dec. 22 Jun. 82

Total 230 1053

Totally, 1283 MRPCs have been produced.

16Jun.7, 2010

Long time stability

More stable at late production stage

17Jun.7, 2010

TOF Time Resolution Summary

2003 to 2009 Operation condition

Time Resolution (ps)VPD

(start time)

TOFr (overall)

TOFr (stop time)

Run III200GeV d+Au ~85 ~120 ~85200GeV p+p ~140 ~160 ~80

Run IV

62GeV (Au+Au) ~55 ~105 ~89

200GeV (Au+Au)

FF/RFF ~27 ~74 ~70

HF ~20 ~74 ~71

Run V200GeV Cu+Cu (TOT) ~ 50 ~92 ~7562GeV Cu+Cu (TOT) ~ 82 ~125 ~94

Run VIII200 GeV d+Au NA NA NA

200 GeV p+p (TOT) ~83 ~112 ~75

Run IX 500 GeV p+p (preliminary) ~85 ~115 ~78

18Jun.7, 2010

Long-strip MRPC

Long-strip readout: save electronics channels. Read out at two ends

Mean time Eliminate the position along the strip Time difference Position information

~3cm

~6cm

STAR TOF ALICE TOF

19Jun.7, 2010

Possible applications

STAR MTD (Muon telescope Detector) CBM TOF Wall (outer part)

MTD

20Jun.7, 2010

LMRPC Prototype-I

Size: 950 x 256 mm2

Readout strip: 25 mm wide, 4 mm gaps between strips

Active area: 870 x 170 mm2

Gas gaps: 10 x 0.25 mm, in 2 stacks

Glass: 0.7 mm

HV electrode: ~200 kΩ/□

21Jun.7, 2010

Photos of construction

22Jun.7, 2010

Trigger area: 20 x 5 cm2

Time reference (T0) TOF MRPC was used to

get 6 segments along the strip.

Gas: 95% Freon + 5% iso-butane

HV=±6.3 kV

LMRPC

Cosmic ray test setup

23Jun.7, 2010

Cosmic ray test results

24Jun.7, 2010

MWPC5MWPC1 MWPC2

MWPC4

TOF1

252” 73”

TOF2

72” 164”449”

LMRPC

GEMsMWPC3

191”56 3381

TOF370”

Upper stream

Down stream

C1, C2

Beam Energy: 32 GeV

FNAL Beam Test (T963)

Beam test setup

25Jun.7, 2010

Beam Test results

Efficiency plateau

Time resolution

1/v ~ 60ps/cm

Position resolution: ~ 1 cm

26Jun.7, 2010

Installed on STAR

Three such LMRPCs have been installed to STAR and successfully taken data since year 2007.

A STAR/MTD proposal was submitted based on these data.

27Jun.7, 2010

LMRPC prototype-II

Readout strips

2.5cm

Readout strips: 2.5 cm x 50 cmGaps between strips: 6 mm

Gas gaps: 10 x 0.25 mm, in 2 stacks

Glass: 0.7 mmHV electrode: ~40 MΩ/□

550 mm

241mm

25 mm

6 mm

28Jun.7, 2010

SSD

Beam test @GSI

FOPI experiment

6m

Proton Beam Pb

2m

42 cmPMT 1,2

PMT 3,4

Platform PlatformPlatformxy

Beam Test setup

SSDTHU MRPC

USTC MRPC

29Jun.7, 2010

T-(t1+t2+t3+t4)/4

T-(t1+t2+t3+t4)/4-f(A)

T-(

t1+

t2+

t3+

t4)/

4ADC

<T-(

t1+

t2+

t3+

t4)/

4>

ADC

MRPC Calibration

MRPC time resolution ~ 67 ps @=±7 kV.(including momentum spread)

((t3+t4)-(t1+t2))/4

PMT Resolution~67 ps

30Jun.7, 2010

Efficiency and resolution plateau

67 ps

97%

31Jun.7, 2010

Position scan (±7 kV)

No significant efficiency drop in the gap

Trigger Area: 2 cm wide

From both “charge sharing” and cross talk.

32Jun.7, 2010

Valid TDCs and valid QDCs (3 sigma above pedestal)Valid TDCs

Cross TalkTrigger on the strip center:“Cross talk” at neighbor strips: <~3%

Trigger Area: 2 cm wide

33Jun.7, 2010

Hits position profile on MRPC

the profile is about 3cm x 2 cm

the following analysis will base on these SSD position cuts and charge cuts

34Jun.7, 2010

Transverse profile—strip center

35Jun.7, 2010

6mm-gap

Transverse profile—strip edge

36Jun.7, 2010

Spatial resolution

1/v~ 60 ps/cm

37Jun.7, 2010

BES/ETOF upgrade

Current ETOF muon: 110ps Electron: 148ps pion: 138ps

(average 1.1GeV for 2 σ π/K separation, but varying is from 0.9 to 1.3 GeV)

MRPC ETOF Not too affected by scattering Total time resolution < 80ps

Non-intrinsic: ~ 50ps MRPC: < 50ps

>1.4GeV for 2 σ π/K separation

38Jun.7, 2010

Design: 36 sectors with overlapping

The edges of MRPC are insensitive Overlapping Space requirement of Front End Electronics 36 sectors instead of 48

39Jun.7, 2010

MRPC prototype design

12 strips, 2 ends read out Length: 8.6-14.1 cm Width: 2.5 cm

Gas gaps: 0.22 mm × 6 × 2 stacks Module thickness:≤22

mm (without the gas box)

40Jun.7, 2010

photos of the assembly

41Jun.7, 2010

Summary

MRPC is successfully designed and mass produced for STAR TOF. The performance is uniform and stable, satisfied the STAR requirements.

Long-strip MRPC shows good performance: Efficiency: > 97% Time resolution: 60-70 ps spatial resolution: less than 1 cm. Cross talk: < 3%

MRPC for other applications is also considered. Look forward to cooperate with NICA/MPD project.

Thank

you!

42Jun.7, 2010

43Jun.7, 2010

MRPC #2 (topview)

Top/bottom pcb

The readout strips are “hollowed-out” alternately.

Removed: 5 mm x 4

Left: 1 mm x 5

Removed: 2.5 mm x 9

Left: 0.25 mm x 10

44Jun.7, 2010

MRPC #3 (topview)

55 cm

24.1cm

2.5cm0.7cm

Gaps between strips: 0.7 cm (upper part)

0.8 cm (lower part)

0.8cm

45Jun.7, 2010

Cross TalkMRPC #2

Valid TDCs and QDCs

46Jun.7, 2010

Efficiency vs. Position

Valid TDCs

HV=±7 kV

47Jun.7, 2010

Valid TDCs and valid QDCs (3 sigma above pedestal)

48Jun.7, 2010

Cross TalkMRPC #3

49Jun.7, 2010

Efficiency vs. Position

Valid TDCs

7mm-gap between strips