A conceptional design of SOLID-TOF

Third workshop on hadron physics in ChinaWang Yi, Tsinghua University

A conceptional design of SOLID-TOF

Outline:• Development of low resistive glass and high rate

RPC• Experience in MRPC mass production• Conceptional design of SOLID-TOF• Conclusions

1

Wang YiDepartment of Engineering Physics

Tsinghua University

Third workshop on hadron physics in ChinaWang Yi, Tsinghua University 2

Introduction of MRPC

Large area, high granularityGood time resolution<100psHigh efficiency> 95%Low cost

Was used or will be used in ALICE, STAR, FOPI, HADES HARP, CBM, Jlab and NICA-MPD

High electric field ~100kV/cm high drift velocity ~220m/ns high Townsend coefficient

Operate in avalanche mode Gas: Freon (electron affinity) iso-butane (UV photon absorption) SF6 (streamer suppressing)

Small gap: 0.2-0.3mm, high resolution

Multi-gaps: high efficiency


TOF with different rate capability

• Low rate TOF

rate <1kHz/cm2, such as ALICE, STAR, FOPI, HADES and MPD

MRPC with float glass with resistivity ~1012cm

• High rate TOF

rate >1kHz/cm2

─ CBM ~20kHz/cm2 in center

─ Jlab ~10kHz/cm2

─ Others

MRPC with low resistive glass with resistivity ~1010cm


/1Rate

World map of MRPC’s rate capability

108 109 1010 1011 1012 1013

102

103

104

105

106

Electron beam (Rossendorf)

Proton beam (GSI)CBM requirement

warm glass

Beijing1 Beijing2 Dresden Lib Coimbra AlICE-muon LHCb ATLAS Warsam CMS-forward CMS-barrel CERN+Bologna CERN+Rio ALICE-TOF STAR Lip+USC)

INR+CBMMax

mum

cou

ntin

g ra

te(k

Hz/

cm2)

Volume resistivity (cm)

streamer mode


Performance of low resistivity glass

Specifications:Maximal dimension: 50cm×50cmBulk resistivity: ~1010.cmStandard thickness: 0.5mm--2mmThickness uniformity: 0.02mmDielectric constant: ~9Surface roughness: <10nmDC measurement: very stable

Thickness distribution

Scanned image of glass


Performance test of glass

0 5 10 15 20 25 30 35

1

2

3

4

5

67

Current(A)

Bulk resitivity(1010cm)

Time(day)C

urr

ent(A

)

2

3

4

5

678910

Bulk

res

istivi

ty(1

010

cm)

This glass was applied with 1000V for about 32days, integrated charge: 1 C/cm2

--roughly corresponding to the CBM life-time over 5 years operation at the maximum particle rate.

0 200 400 600 800 10001E8

1E9

1E10

1E11

Applied voltage(V)

Bulk

res

istivi

ty(

cm)

20°C 30°C 40°C 50°C 60°C 70°C

Resistivity decreases with temperature

Resistivity is very stable in DC measurement


2 cm2 cm

13 cm

Colloidal graphite: 2M /Gas gap:10×0.22mmGlass: 0.78mm,1mm resistivity: ～ 1010Ω.cm

FEE

+

-

Prototype of high rate MRPC (pad-readout)


Cosmic ray test

Cosmic ray test: Time resolution: ~80ps Efficiency: >95% 5.2 5.4 5.6 5.8 6.0 6.2 6.4

50

55

60

65

70

75

80

85

90

95

100

Eff

icie

nc

y (

%)

High voltage (kV)

0

10

20

30

40

50

60

70

80

90

100

Str

eam

er r

atio

(%

)


Test results by proton beam @GSI

2.3 2.4 2.5 2.6 2.7 2.870

75

80

85

90

95

100

Efficiency(%)Time resolution(ps)

Applied voltage(kV/gap)

Effi

cien

cy(%

)

50

60

70

80

90

100

110

120

130

140

150

Tim

e re

solu

tion(p

s)

0 5 10 15 20 2580

85

90

95

100

Efficiency(%) Time resolution(ps)

Particle flux (kHz/cm2)E

ffici

ency

(%)

60

70

80

90

100

110

120

130

Tim

e re

solu

tion(p

s)

Efficiency and time resolution as a function of high voltage at a rate of about 800Hz/cm2

When the particle flux increases every 5 kHz/cm2, the efficiency decreases by 1% and the time resolution deteriorates by 4 ps.

In this test, T0 is about 70ps, the time resolution is deteriorated.


• Source: 30MeV electron• Trigger: S1^S2^S3^S4^S6^RF• Beam size: 7cm2

• MRPC and S6 are placed on movable columns.

• S6: 35mm*35mm*5mm• Reference time: RF signal from

ElBE• CAEN TDC 1290 N: 24.5 ps/bin• QDC: V965: 25 fc/bin• Efficiency is determined by the

scaler.• Gas: 85% Freon+5% Iso+ 10%SF6

trigger

rpc

Counts

CountsEff

Beam Test @Rossendorf


HV scan of pad MRPC

• Time resolution: 45ps• Efficiency: 97％


Rate scan of pad MRPC

• Rate: >30kHz/cm2

• Time resolution: <60ps• Efficiency: >90％


Time resolution of all pads (1)

60 59 57 65 73 62

58 54 62 77 63 65

44 43 40 50 60 47

42 36 46 66 48 51

Time resolution (ps) (T0 is subtracted)

Intrinsic time resolution (The jitter of T0, FEE and TD are all subtracted)

10 kHz/cm2


Time resolution of all pads (2)

72 74 68 71 79 79

73 73 79 90 78 81

60 62 54 58 70 68

61 61 68 80 67 70

Time resolution (ps)

Intrinsic time resolution (ps)

50 kHz/cm2

Good

unifo

rmity


Prototype of high rate MRPC (strip-readout)

Colloidal graphite: 2M /Gas gap: 10×0.25mmGlass: 0.78mm,1mm resistivity: ～ 1010Ω.cm


HV scan of strip MRPC (Rosendorf)

Working voltage: 6.45 kV

• Time resolution: 45ps

• Efficiency: 97％


Rate scan of strip MRPC

• Rate: >30kHz/cm2

• Time resolution: <60ps• Efficiency: >90％


Position Scan

2 3 1

Rpcy

-20 -10 0 10 20 30 400

20

40

60

80

100 "or" eff

strip1

strip2

strip3

"and" eff

Effi

cie

ncy(%

)

Rpcy(mm)

-20 -10 0 10 20 30

70

80

90

100

110strip1

strip2

strip3

Tim

e r

esolu

tion(p

s)

Rpcy(mm)

-20 -10 0 10 20 30 400

20

40

60

80

100 "or" eff strip1 strip2 strip3 "and" eff

Effici

ency

(%)

Rpcy(mm)

MRPC#3

MRPC#4


Third workshop on hadron physics in ChinaWang Yi, Tsinghua University 2020 20

MRPC workshop @ Tsinghua


1/2 3/4 5/6 7/8 11/129/10 1/2 3/4 5/6 7/8 11/129/10 1/2 3/4 5/6 7/8

2006 2007 2008

Prod Start

132 MRPCs

768 MRPCs

1856 MRPCs

2944 MRPCs

4032 MRPCs

MRPC production scheme for STAR

MRPC production was finished in September of 2008. In Tsinghua: 3100 MRPC have been produced; 2951 Modules passed QA, yield >95% ; 2840 modules shipped to UT Austin .

Great

success!


PID of STAR-TOF

TOF

PID capability:

/k ~1.6 GeV/c,

(,k)/p ~ 3.0 GeV/c

Observation of Anti-Helium

Nature Vol 473,(2011) 353-356


1/2 3/4 5/6 7/89/1011/12 1/2 3/45/6 7/8 9/1011/12Plan 2011 2012

Start20 LMRPCs40 LMRPCs60 LMRPCs80 LMRPCs

100 LMRPCs115 LMRPCs

R&D and production of STAR-MTD


Experimental layout of SoLID



Requirement for TOF

• /k separation up to 2.5GeV/c

─ assume 9m path-length: (20:1 kaon rejection at 2.5GeV/c)

─ High rate MRPC

─ <80ps

─ Rate capability>30kHz/cm2

─ Estimated rates: 10kHz/cm2

─ Active area: 10m2

─ Granularity: A~ 32—63cm2


TOF Design- MRPC Module

Structure of one module• Low resistive glass• 10×0.25mm gaps• 11 strips• strip width: 25mm• interval: 3mm• differential readout

This module will be tested with cosmic ray and beam!


TOF structure

SM number ： 50Each SM contain 3 modulesEach module consists of 11 stripsStrip width ： 25mmInterval ： 3mmShortest strip ： 13cmLongest strip ： 25cmTotal electronic channels ： 3300

Gas box


TOF electronics

• Fast preamplifier ： Maxim3760 (RICE Univ.) Ninos TOT (ALICE) Padi TOT (GSI) CAD TOT(Tsinghua) • QDC (CAEN, 25fC/bin)• TDC HPTDC (ALICE, 25ps/ch) GET4 (GSI, 25ps/ch) FPGA TDC (?)

• DAQ


CAD: Current Amplifier and Discriminator

0is Vout

ith

NM0

PM0

iin iout

1:N

Cin

M1 M2

Current Amp

Current Disc.

1.52mm

1.52

mm

Fully Current Mode Simple, Compact and Less power consumption


Key parameters

CAD-1.0 PADI-1 NINO-25 NINO-13

Peaking time ~1ns <1ns 1ns 0.6ns

Linear range 1000A*1 -60-60A*1 0-100fC*2 0-100fC*2

Time jitter <20ps, rms*3 <15ps, rms*4 10-25ps, rms 6-25ps, rms

Power consumption 10mW/ch <30mW/ch 30mW/ch 5mW/ch

Input type S.E. DIFF. DIFF. DIFF.

Input impedance 50-70 48-58 30-100 30-100

Discriminator threshold 263A*1 10-400A*1 20-100fC*2 20-100fC*2

CMOS process 0.35m 0.18m 0.25m 0.13m

*1: for current pulse with 0.3ns rise time, 1-2ns FWHM, and 0.3ns fall time*2: for square current pulse with 200ps width*3: for 200A input current*4: for 100A input current


A solution for TOF system

CAD ASIC

FPGA TDC

FEE Board

Digitizer Board

IN+

IN-

DAQ Board

Ethernet

MRPC

MRPC technology will be used to construct TOF. Combine ASIC FEE and FPGA TDC and Ethernet DAQ s


Conclusions

• Development of low resistive glass with resistivity ~

1010Ωcm, very good performance.• Development of pad- and strip- readout high rate

MRPCs, rate capability>25kHz/cm2, time

resolution<60ps. The glass and detector is adopted by

CBM to construct TOF. • Conceptional design of SOLID-TOF.• It can also be use in other experiments such as NICA-

MPD.


Thanks for your attention!

Documents

A conceptional design of SOLID-TOF