长读出条 mrpc 性能研究 孙勇杰 key laboratory of technology of particle detection and...
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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
NanChang University 3Apr. 18, 2010
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
NanChang University 4Apr. 18, 2010
Possible applications
STAR MTD (Muon telescope Detector) CBM TOF Wall (outer part)
MTD
NanChang University 5Apr. 18, 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/□
NanChang University 6Apr. 18, 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
NanChang University 7Apr. 18, 2010
Cosmic ray test results
NanChang University 8Apr. 18, 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
NanChang University 9Apr. 18, 2010
Beam Test results
Efficiency plateau
Time resolution
1/v ~ 60ps/cm
Position resolution: ~ 1 cm
NanChang University 10Apr. 18, 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
NanChang University 11Apr. 18, 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
NanChang University 12Apr. 18, 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
NanChang University 13Apr. 18, 2010
Efficiency and resolution plateau
67 ps
97%
NanChang University 14Apr. 18, 2010
Position scan (±7 kV)
No significant efficiency drop in the gap
Trigger Area: 2 cm wide
From both “charge sharing” and cross talk.
NanChang University 15Apr. 18, 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
NanChang University 16Apr. 18, 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
NanChang University 17Apr. 18, 2010
Transverse profile—strip center
NanChang University 18Apr. 18, 2010
6mm-gap
Transverse profile—strip edge
NanChang University 19Apr. 18, 2010
Combined
NanChang University 20Apr. 18, 2010
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!
NanChang University 21Apr. 18, 2010
NanChang University 22Apr. 18, 2010
NanChang University 23Apr. 18, 2010
Longitudinal
Valid TDC Valid TDC & QDC
NanChang University 24Apr. 18, 2010
charge vs position
NanChang University 25Apr. 18, 2010
Signal Charge vs Position
near the edge of stripat the middle of strip
NanChang University 26Apr. 18, 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
NanChang University 27Apr. 18, 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
NanChang University 28Apr. 18, 2010
Cross TalkMRPC #2
Valid TDCs and QDCs
NanChang University 29Apr. 18, 2010
Efficiency vs. Position
Valid TDCs
HV=±7 kV
NanChang University 30Apr. 18, 2010
Valid TDCs and valid QDCs (3 sigma above pedestal)
NanChang University 31Apr. 18, 2010
Cross TalkMRPC #3
NanChang University 32Apr. 18, 2010
Efficiency vs. Position
Valid TDCs
7mm-gap between strips
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