Zebo Tang, 高能核物理导论 19/21/2009

唐泽波中国科学技术大学近代物理系

飞行时间计数器 TOF 的刻度，性能和升级

Zebo Tang, 高能核物理导论 29/21/2009

Timing Resolution before Calibration

Resolution = 124 psCalibration is necessary

Zebo Tang, 高能核物理导论 39/21/2009

时间测量过程pulse

甄别TDC

stop

gate/start

Zebo Tang, 高能核物理导论 49/21/2009

TDC 微分非线性 (DNL)

TDC

Cou

nts

Zebo Tang, 高能核物理导论 59/21/2009

TDC 积分非线性 (INL)

TDC

INL=

TD

C-i

Zebo Tang, 高能核物理导论 69/21/2009

INL 修正

2.7 0.9

Zebo Tang, 高能核物理导论 79/21/2009

pion 样本选择

Momentum p (GeV/c)

dE

/dx

(KeV

/cm

)

Track length L, momentum p and mass m TOFexpected

Compare to TOFmeasured

TOFmeasured- TOFexpected ~0 for pion

Zebo Tang, 高能核物理导论 89/21/2009

T0 修正

不同的信号传播时间不同的延迟电缆。。。

Zebo Tang, 高能核物理导论 99/21/2009

T0 修正

TOFmeasured – TOFexpected (ns)

Cou

nts

高斯函数拟合将 TOFmeasured – TOFexpected 的平均值平移到零

Zebo Tang, 高能核物理导论 109/21/2009

时幅（ T-A ）修正tT1T2

幅度越小，时间越大

Zebo Tang, 高能核物理导论 119/21/2009

T-A 关系

)()('

)(2

ADCfTDCADCTDC

x

e

xx

d

x

c

x

baxf

Zebo Tang, 高能核物理导论 129/21/2009

击中位置修正

Signal output

Scan area

beam

~6 cm

光传播 1cm 需要的时间？信号在读出条上的传播速度 ?

Zebo Tang, 高能核物理导论 139/21/2009

T-Z 关系

propagation speed ：~45ps/cm

Zebo Tang, 高能核物理导论 149/21/2009

2005 Cu+Cu, 62 GeV

2005 Cu+Cu, 200 GeV

2009 p+p, 500 GeV2008 p+p, 200 GeV

TOF Timing Resolution

Zebo Tang, 高能核物理导论 159/21/2009

TOF Time Resolution Summary

Operation condition

Time Resolution (ps)VPD

(start time)

TOFr (overall)

TOFr (stop time)

Run III200GeV d+Au ~85 ~120 ~85200GeV p+p ~140 ~160 ~80

Run IV

62GeV (Au+Au) ~55 ~105 ~89

200GeV (Au+Au)

FF/RFF ~27 ~74 ~70

HF ~20 ~74 ~71

Run V200GeV Cu+Cu (TOT) ~ 50 ~92 ~7562GeV Cu+Cu (TOT) ~ 82 ~125 ~94

Run VIII200 GeV d+Au NA NA NA

200 GeV p+p (TOT) ~83 ~112 ~75

Run IX 500 GeV p+p (preliminary) ~85 ~115 ~78

Zebo Tang, 高能核物理导论 169/21/2009

Hadron PID

TOF alone:

/k ~1.6 GeV/c, (,k)/p ~ 3.0 GeV/c

TPC alone:/k ~0.7 GeV/c,

(,k)/p ~1.1 GeV/c

STAR Collaboration, PLB 616 (2005) 8

e

πK

p

TPC

TOF

Zebo Tang, 高能核物理导论 179/21/2009

Light hadron with TOF

TPC only

Au+Au

p+p STARPRL92,112301(2004)

With ONETOF Prototype

STAR, PLB 616, 8 (2005); PRL 97, 152301 (2006)

Zebo Tang, 高能核物理导论 189/21/2009

Electron and muon ID

arXiv: 0805.0364STAR, PRL 94, 062301, (2005)

|1/β-1|<0.03

Electron: pT>0.2 GeV/cMuon: pT<0.25 GeV/c

Zebo Tang, 高能核物理导论 199/21/2009

Heavy Flavor with TOF

e

D0K

arXiv: 0805.0364

Very helpful for open charm and hidden charm physics

Zebo Tang, 高能核物理导论 209/21/2009

Light Nuclei with TOF

Haidong Liu (STAR Collaboration), JPG 34, S1087 (2006), QM2006

Zebo Tang, 高能核物理导论 219/21/2009

Resonance with TOFAu+Au 200GeV

(1029) (1029)

*K (892) *K (892)

Enhanced by a factor of ~4

Enhanced by a factor of ~2

Only one TOF track

Yichun Xu et al., NIM A596, 186 (2008)

Yichun Xu

Zebo Tang, 高能核物理导论 229/21/2009

Resonance with two TOF tracks

500 GeV p+p~75% TOF installed~2 M events for these plots

S/B:K* ~0.12: ~3.2

Yanfei Shen

TPC not well calibrated

Zebo Tang, 高能核物理导论 239/21/2009

对 STAR 基于 EMC 的 trigger 能力的改善

x0.05x0.05)

~5X0

High Tower trigger: ET> a few GeVQuarkonium trigger: J/,

Zebo Tang, 高能核物理导论 249/21/2009

TOF Match Rejection Power

Lucas M. Lima

L2 triggered events

Zebo Tang, 高能核物理导论 259/21/2009

Upgrades

Zebo Tang, 高能核物理导论 269/21/2009

STAR Muon Telescope Detector (MTD)

A pseudo detector with scintillator covering the whole iron bars and left the gaps in-between uncovered.

1. muon efficiency: 35-45%, pion efficiency: 0.5-1%2. muon-to-pion enhancement factor: 50-1003. muon-to-hadron enhancement factor: 100-1000 including track matching, tof

and dE/dx4. dimuon trigger enhancement factor from online trigger: 10-50 (Guoji Lin, DNP06)

Detection efficiency

pT (GeV)

pionmuon

This together with DAQ1000 will greatly enhance our capability of J/ and other dilepton program in RHIC II and future QCD Lab

Lijuan Ruan

Zebo Tang, 高能核物理导论 279/21/2009

Long-strip MRPC R&D95 cm

25

cm

Pad size of STAR TOFLMRPC

2.5 cm

Large coverageLow costs on electronics

Zebo Tang, 高能核物理导论 289/21/2009

Beam Test Results

Efficiency Plateau

Time resolution Plateau

Yongjie Sun et al., NIM, A593, 307 (2008)

At E~100 kV/cm (HV=±6300 V): Efficiency ~98% Resolution <70 ps

Zebo Tang, 高能核物理导论 299/21/2009

Beam Test Results

Signal propagation velocity:

~ 60ps/cm The time difference: (T) ~ 55ps Position resolution: ~ 1 cm

USTC module, HV=6300V, run30-33

Position calculated from timing on two ends

Yongjie Sun et al., NIM, A593, 307 (2008)

Zebo Tang, 高能核物理导论 309/21/2009

CBM TOF Wall中间： 高技术率 MRPC外围：长读出条 MRPC

Zebo Tang, 高能核物理导论 319/21/2009

Efficiency and resolution plateau

65 ps

97%

Zebo Tang, 高能核物理导论 329/21/2009

Cross Talk

Hit at the middle of the pad:

<Cross talk> at neighbor pads: 2%

Trigger Area: 1 cm wide

<Cross talk> at next-to-neighbor pads: ~1%

Zebo Tang, 高能核物理导论 339/21/2009

High counting rate MRPC

0 5 10 15 20 25 30 3560

65

70

75

80

85

90

95

100

105

110

Efficiency(%) Time resolution(ps)

Particle rate(kHz/cm2)

Eff

icie

ncy

(%)

70

80

90

100

110

120

130

140

150

160

Tim

e resolu

tion(p

s)

+HV

-HV

EE1

Yi Wang

Zebo Tang, 高能核物理导论 349/21/2009

BESIII High Resolution MRPC R&D

Cheng Li

Zebo Tang, 高能核物理导论 359/21/2009

Beam Test Results of a 24-gaps MRPC

Shaohui An et al., NIM A594, 39-43 (2006)

~21 ps

9/21/2009 Zebo Tang, 高能核物理导论 36

A Small Animal PET with (M)RPCs

• Modules of n-stacked timing RPCs.

• High acceptance geometry > 90%.

• Fully 3D measurement of the interaction point of the photon. No parallax error.

• Very high spatial resolution < 0.5 mm (FWHM).

• High timing resolution < 1 ns, improve the random events rejection.

• Efficiency 10% (sensitivity 6 cps/KBq).

• Low cost vs. scintillator based implementations.

• Compatible with Magnetic Resonance Imaging.

Incident photon

Gas gap

The detection The scanner

Compton or photoelectric interaction

....e-

4

Alberto Blanco

Zebo Tang, 高能核物理导论 379/21/2009

Summary

TOF 刻度： HPTDC INL, T0, 时幅修正，位置修正

STAR-TOF 大大提高了稳定带电强子，电子，低动量 muon, 共振态粒子等的鉴别水平

基于 MRPC 技术的各种探测器在蓬勃发展

Zebo Tang, 高能核物理导论 389/21/2009

Home work

STAR-TOF 的安装对 D0 的重建是否有很大的帮助？如果有的话，在那些方面 ? 对 KS 和呢？