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MRPC Beam Test @ GSI
Yongjie Sun
University of Science and Technology of China
14th CBM collaboration meeting 206 Oct. 2009
Index
Test setup Preliminary results of 3 prototypes Summary
14th CBM collaboration meeting 306 Oct. 2009
Accelerator
14th CBM collaboration meeting 406 Oct. 2009
Setup
Our Beam Test Experiment
FOPI at Cave B
14th CBM collaboration meeting 506 Oct. 2009
6m
Setup
ProtonBeam
Pb
2m
42 cmPMT 1,2PMT 3,4
PMT 5,6TSU MRPC
USTC MRPC
Platform PlatformPlatform
xy
14th CBM collaboration meeting 606 Oct. 2009
Photo of the setup
14th CBM collaboration meeting 706 Oct. 2009
Beam
Proton beam,Kinetic energy: 3.5 GeV/c
14th CBM collaboration meeting 806 Oct. 2009
DAQ Logic
T
D
C
Q
D
C
PMT 1-4(5)
DiscriminatorNIMECL VULOM, Logic
Delay NIMECL
LMRPC1-6 (left)7-12(right)
FEE
Delay Discriminator NIMECL
Delay
Delay
Gate
Trigger area: 2 cm x 4 cm (without back_scint.)
STOP
14th CBM collaboration meeting 906 Oct. 2009
Index
Test setup Preliminary results of 3 prototypes Summary
14th CBM collaboration meeting 1006 Oct. 2009
MRPC structure (endview)
5 x 250μm gaps
5 x 250μm gaps
Readout strips
HV
2.5cm
Readout strips: 2.5 cm x 50 cmHV electrode: Licron spray ~40 MΩ/□
Made of window glass of 0.7 mm thick
14th CBM collaboration meeting 1106 Oct. 2009
MRPC #1 (topview)
55 cm
24.1cm
2.5cm
0.6cm
Gaps between strips: 0.6 cm
14th CBM collaboration meeting 1206 Oct. 2009
MRPC #1
+iso-butane 5%+Freon
14th CBM collaboration meeting 1306 Oct. 2009
ADC1 ADC2
ADC3 ADC4
<t 1
-(t 3
+t 4
)/2>
ADC1
<t 2
-(t 3
+t 4
)/2>
ADC2
<t 3
-(t 1
+t 2
)/2>
ADC3ADC4
PMT calibration
<t 4
-(t 1
+t 2
)/2>
((t3+t4)-(t1+t2))/4
Resolution~67 ps
14th CBM collaboration meeting 1406 Oct. 2009
T-(t1+t2+t3+t4)/4
T-(t1+t2+t3+t4)/4
T-(
t1+
t2+
t3+
t4)/
4ADC
<T-(
t1+
t2+
t3+
t4)/
4>
ADC
MRPC CalibrationIntrinsic timing resolution = 67 ps (including momentum spread)
14th CBM collaboration meeting 1506 Oct. 2009
Efficiency and resolution plateau
65 ps
97%
14th CBM collaboration meeting 1606 Oct. 2009
Position scan (±7 kV)
No significant efficiency drop in the gap
Trigger Area: 2 cm wide
From both “charge sharing” and cross talk.
14th CBM collaboration meeting 1706 Oct. 2009
Cross Talk
Trigger on the strip center:
“Cross talk” at neighbor strips: 3%
Trigger Area: 2 cm wide
“Cross talk” at next-to-neighbor strips: ~2%
Require valid TDC on two ends
14th CBM collaboration meeting 1806 Oct. 2009
TDC vs. QDCValid TDCs and valid QDCs (3 sigma above pedestal)
Valid TDCs
14th CBM collaboration meeting 1906 Oct. 2009
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
14th CBM collaboration meeting 2006 Oct. 2009
MRPC #2
Valid TDCs and QDCs
14th CBM collaboration meeting 2106 Oct. 2009
Efficiency vs. Position
Valid TDCs
14th CBM collaboration meeting 2206 Oct. 2009
Valid TDCs and valid QDCs (3 sigma above pedestal)
14th CBM collaboration meeting 2306 Oct. 2009
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
14th CBM collaboration meeting 2406 Oct. 2009
MRPC #3
14th CBM collaboration meeting 2506 Oct. 2009
Efficiency vs. Position
Valid TDCs
14th CBM collaboration meeting 2606 Oct. 2009
Summary
Three prototypes were successfully tested. Efficiency: > 97% Time resolution: 60-70 ps Cross talk: < 3%
With position from silicon detectors, the data will be further analyzed.
Thank
you!
14th CBM collaboration meeting 2706 Oct. 2009
14th CBM collaboration meeting 2806 Oct. 2009
Longitudinal
14th CBM collaboration meeting 2906 Oct. 2009
Double hit
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