star-mtd workshop@ustc, march 30 th -april 1 th, 2011 wang yi, tsinghua university 1 final design...

STAR-MTD workshop@USTC, March 30th-April 1th , 2011Wang Yi, Tsinghua University 1

Final design and plan for LMRPC production

Outline:• LMRPC structure• Material• Production procedure and QC• Performance test• Time schedule

Wang Yi on behalf of Tsinghua and USTC

Department of Engineering Physics,Tsinghua University


A large area of muon telescope detector (MTD) at mid-rapidity, allows for the detection of•di-muon pairs from QGP thermal radiation, quarkonia, light vector mesons, possible correlations of quarks and gluons as resonances in QGP, and Drell-Yan production

•single muon from the semi- leptonic decays of heavy flavor hadrons

•advantages over electrons: no conversion, much less Dalitz decay contribution, less affected by radiation losses in the detector materials, trigger capability in Au+Au

•trigger capability for low to high pT J/ in central Au+Au collisions excellent mass resolution, separate different upsilon states e-muon correlation to distinguish heavy flavor production from initial lepton pair production

STAR Muon Telescope Detector


Concept of Design of the STAR-MTD

A detector with long-MRPCs covers thewhole iron bars and leave the gaps in- between uncovered. Acceptance: 45% at ||<0.5

117 modules, 1404 readout strips, 2808 readout channels

Long-MRPC detector technology, HPTDCelectronics (same as STAR-TOF)

Inner glass: 549 mm × 870 mm

Licron electrode: 549 mm × 880 mmOuter glass: 559 mm × 890 mm

Mylar layer: 564 mm × 895 mmHoneycomb: 559 mm × 890 mm

PC board: 580 mm × 915 mm

Strip: 38 mm × 870 mmInterval: 6 mm

Spacer: fishing lineGas gap: 0.25 mm

Inner glass: 0.7 mmOuter glass: 1.1 mm

PC board: 0.9 mm honeycomb: 10 mm

Mylar: 0.15 mm Strip: 0.035 mm


MTD requirements:

• Time resolution less than 100 ps, spatial resolution ~ 1 cm.

• The mechanics design must allow a convenient replacement of

individual MTD box and access to the BEMC box.

• The system must be able to operate in the fringe field from 0.5 Tesla

STAR magnet field.

• The system must operate at low noise rate. The total noise rate should

be less than 0.5 M Hz, 1 Hz/cm2.

• The system must be safe, meet all BNL safely requirements.

• The system must not impair the performance of other STAR detectors.

MTD System Requirement


Inner glass: 549 mm × 870 mm

Licron electrode: 549 mm × 880 mmOuter glass: 559 mm × 890 mm

Mylar layer: 564 mm × 895 mmHoneycomb: 559 mm × 890 mm

PC board: 580 mm × 915 mm

Strip: 38 mm × 870 mmInterval: 6 mm

Spacer: fishing lineGas gap: 0.25 mm

Inner glass: 0.7 mmOuter glass: 1.1 mm

PC board: 0.9 mm honeycomb: 10 mm

Mylar: 0.15 mm Strip: 0.035 mm

Structure of LMRPC module

For assuring the stable performance, we will compare the performance between 5 and 6 gaps modules.


Structure of LMRPC module


76 78 80 82 84 86 88 90 92 94 96 98 10030

35

40

45

50

55

60

65

70

75

80

85

90

95

100

105

Efficiency @ Freon/iso-Butane/SF6 : 95%/ 5%/0% Time resolution @ 95%/5%/0% Efficiency @ 94%/ 5%/1% Time resolution @ 94%/ 5%/1%

E (kV/cm)

Effi

cien

cy (%

)

95%

70

75

80

85

90

95

100

105

110

115

120

Tim

e resolu

tion (p

s)

78 80 82 84 86 88 90 92 94 96 98 100 102 10450

55

60

65

70

75

80

85

90

95

100

Efficiency Time resolution

E (kV/cm)

Effi

cien

cy (%

)

60

70

80

90

100

110

120

Tim

e resolu

tion (p

s)

95%

Performance of LMRPC

Cosmic ray test Beam test

Time resolution ~ 70ps, efficiency> 95%


94%Freon/5%iso-butane/1% SF695%Freon/5%iso-butane

Noise < 0.6 Hz/cm^2 @ 7200V Noise < 0.4 Hz/cm^2 @ 7200V

Noise level @different gas mixture

LMRPC meets the MTD requirement!


Material Type and manufacturer Dimension (mm) Tolerance (mm) Quantity

Outer glass Beijing 8905591.1 ±0.5, ±0.5 ,±0.02 2

Inner glass Bejing 8705490.7 ±0.5, ±0.5, ±0.02 5

Graphite electrode Colloidal graphiteSR~4 Mohm/

888×557×0.1 -0.5 2

Mylar film Dupont Corp. 895×564×0.15 ±0.1 2

Honeycomb board Aoxing Corp. 890×559×10 ±1.0, ±1.0 2

PCB ShengYi Corp.G10

915×580×0.912strips, 38×870/strip

±0.5 2

L-shaped and cylinder supporter

Weishi Corp.Polycarbonate

height:4.8 -0.05 12

Nylon wire Japan Diameter 0.25 ±0.005

RTV CAF4, France

HV lead 15kV, USA 60cm ±1 2

Signal lead 34 ribbon cable, USA 60cm ±1 4

The materials for one LMRPC module

STAR-MTD workshop@USTC, March 30th-April 1th , 2011Wang Yi, Tsinghua University

Chinese LMRPC production

• The LMRPC production is the same as STAR-TOF MRPC production, we have two production sites in China.

Tsinghua University (60%) University of Science and Technology of China (40%)

• Facilities and tools ensure quality.

• Each site with QA and testing facility.

• Web-based module-data-base accessible at the assembly sites.

10


1/2 3/4 5/6 7/89/1011/121/2 3/45/6 7/8 9/1011/12

Plan 2011 2012

Start20 LMRPCs40 LMRPCs60 LMRPCs80 LMRPCs

100 LMRPCs115 LMRPCs

LMRPC manufacture milestones

11

VECC will produce 10% (15 ) modules


Inner glass

outer glass

Mylar Honeycombboard

PCB Graphite Nylonwire

…

Material procurement

CheckElectrodeassembly

Yes

LMRPCassembly

Check distanceBetween PCBSolder signal

cable

Yes

No

Check continuity

No

Final check

Test amplitude and time

LabelYes Yes

Yes

NoNo

No

Procedures of construction and QC


Quality control on the material

• Glass– Measure the dimensions – Check the surface quality

• Pcb– Dimensions, – the scratch on the strips

• Honeycomb – Dimensions, surface quality

• Mylar foil: thickness, holes

• Fishing line– Dimension check of each coil

• Support block: thickness

Material with faults will be returned back to factory.


HV cables and signal connection

• Rice and UT Austin will provide us HV and signal cables


MRPC put in box

Exercise time: 10 hoursHV:±7200V

Measure current & noise rate

Measure QDC & TDC 24×3 hours

Flushing with gas 48 hours, 100ml/min

LMRPC Testing Procedure

For the first batch of

LMRPC modules (about 20

modules), 100% strips will

be tested for efficiency and

time resolution.

Later, 33% strips will be

tested.


Nominal Minimum Maximum

Length 915mm 914.2mm 915.8mm

Width 580mm 579.2mm 580.8mm

Thickness 30mm 28.5mm 31.5mm

LMRPC mechanical specifications

16


Testing conditions Specifications

Working gas: 95% F134A+5% iso-butane

Leakage current: < 40 nA

HV: 14.4kV Noise rate: < 1Hz/cm2

FEE threshold: 30mV Efficiency : > 90%

Timing resolution < 120 ps for 90% strips

MRPC performance requirement

17


Time schedule• 2011.4 – 2011.6 finalizing the design

Design modules with 5 and 6 gaps, test performance, detailed comparison.

Make a conclusion on the performance of different structure

with/without glue.

Help VECC to establish test system, production tools and some materials…

Module production:

• 2011.6 – 2011.12 20%

• 2012.1 – 2012.6 40%

• 2012.7 – 2012.12 40%

star-mtd workshop@ustc, march 30 th -april 1 th, 2011 wang yi, tsinghua university 1 final design...

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