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Beam Test Results of

USTC LMRPC modules (50cm)

Yongjie Sun

presnted by Hongfang Chen

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Outline

Long-strip MRPC structure Results of August beam test at GSI Summary

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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

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MRPC #1 (topview)

55 cm

24.1cm

2.5cm

0.6cm

Gaps between strips: 0.6 cm

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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

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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

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6m

Setup

ProtonBeam

Pb

2m

42 cmPMT 1,2PMT 3,4

PMT 5,6TSU MRPC

USTC MRPC

Platform PlatformPlatform

xy

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Photo of the setup

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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

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ADC1 ADC2

ADC3 ADC4

PMT calibration<

t 1-(

t 3+

t 4)/

2>

ADC1

<t 2

-(t 3

+t 4

)/2>

ADC2

<t 3

-(t 1

+t 2

)/2>

ADC3 ADC4

<t 4

-(t 1

+t 2

)/2>

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

Resolution~67 ps

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

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

T-(

t1+

t2+

t3+

t4)/

4

ADC

<T-(

t1+

t2+

t3+

t4)/

4>

ADC

MRPC CalibrationIntrinsic timing resolution = 67 ps (including momentum spread)

HV=7kV

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Efficiency and resolution plateau

67 ps

97%

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Position scan (±7 kV)

No significant efficiency drop in the gap

Trigger Area: 2 cm wide

From both “charge sharing” and cross talk.

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

Cross TalkMRPC #1

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

Trigger Area: 2 cm wide

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Cross TalkMRPC #2

Valid TDCs and QDCs

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Efficiency vs. PositionMRPC #2

Valid TDCs

HV= 7kV

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Valid TDCs and valid QDCs (3 sigma above pedestal)

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Cross TalkMRPC #3

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Efficiency vs. PositionMRPC #3

Valid TDCs

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Track information using the data of SSD

the following analysis is based on the instruction of : Y.P. Zhang,P.-A. Loizeau Data structure of final NTUPLE and a short description about how to use the silicon tracking system

the data files used : run_0005.root, run_0006.root, ......, run_0020.root,where the USTC-MRPC was settled at the same position. run_0021.root, the MRPC moved by 12mm.

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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

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Tranverse profile-- efficiency vs positionfor MRPC#1

run0005-0020

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Efficiency vs Positionfor MRPC#1

data file, run_0021.root

edge effects

6mm-gap

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Combined data

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Summary

The cross talk for neighbour strip ~3%for modules MRPC#1, 2, 3. (50cm strip)

Next step 1m long strip

Thank You ！

谢谢！

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Signal Charge vs Position

near the edge of stripat the middle of strip

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Time Resolution of PMT timing

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

after T-A correction

Sigma(pmt) = 2.08 *35ps = 73ps

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RPC time resolution

cuts: SSD cust PMT cuts

resolution:sigma(rpc) = 69 ps

35ps/ch

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Hit tranverse profile

position distribution

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pmt resolution vs position

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

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rpc

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rpc resolution vs position

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eff and reo vs position

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Longitudinal

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edge effects

the profile is also quite clear,

and we can see that the beam hits between two strips of the MRPC

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(2) pmt cuts: pmt-pair charge: q1+q2, q3+q4 take out 5% at the low range side, and take a

nother 25% at the high range side time difference: T1-T2, T3-T4 2.5%, 2.5% position difference: (T1-T2)-(T3-T4) 2.5%, 2.5% time of flight: ((T3+T4)-(T1+T2))/4 0.5%, 0.5%

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edge effects