长读出条 MRPC 性能研究孙勇杰 Key Laboratory of Technology of Particle Detection and Electronics, USTC-IHEP, CAS Center of Particle Physics and Technology, USTC

长读出条 MRPC 性能研究

孙勇杰

Key Laboratory of Technology of Particle Detection and Electronics, USTC-IHEP, CAS

Center of Particle Physics and Technology, USTC

NanChang University 2Apr. 18, 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


MRPC—signal pickup

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


Possible applications

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

MTD


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/□


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


Cosmic ray test results


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


Beam Test results

Efficiency plateau

Time resolution

1/v ~ 60ps/cm

Position resolution: ~ 1 cm


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


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


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


Efficiency and resolution plateau

67 ps

97%


Position scan (±7 kV)

No significant efficiency drop in the gap

Trigger Area: 2 cm wide

From both “charge sharing” and cross talk.


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


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


Transverse profile—strip center


6mm-gap

Transverse profile—strip edge


Combined


Summary

Long (0.5 m, 0.9 m) readout-strip MRPCs were successfully constructed and tested. Efficiency: > 97% Time resolution: 60-70 ps spatial resolution: less than 1 cm. Cross talk: < 3%

LMRPC shows prospective application as TOF in low multiplicity environments.

Two LMRPCs (0.9m) have already been installed to STAR as part of the MTD detector and have successfully taken data since year 2007.

Thank

you!




Longitudinal

Valid TDC Valid TDC & QDC


charge vs position


Signal Charge vs Position

near the edge of stripat the middle of strip


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


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


Cross TalkMRPC #2

Valid TDCs and QDCs


Efficiency vs. Position

Valid TDCs

HV=±7 kV


Valid TDCs and valid QDCs (3 sigma above pedestal)


Cross TalkMRPC #3


Efficiency vs. Position

Valid TDCs

7mm-gap between strips

Documents

长读出条 MRPC 性能研究 孙勇杰 Key Laboratory of Technology of Particle Detection and Electronics, USTC-IHEP, CAS Center of Particle Physics and Technology, USTC

长读出条 MRPC 性能研究孙勇杰 Key Laboratory of Technology of Particle Detection and Electronics, USTC-IHEP, CAS Center of Particle Physics and Technology, USTC