Performance of High Resolution Time-of-Flight detector for Study of Identified Hadron Productionat RHIC-PHENIX experiment

•Contents–PHENIX-TOF

–Basic Design

–Construction/Operation

–Performance

–Summary

Univ.of Tsukuba:A.Kiyomichi, M.Aizawa, M.Ono, S.Kato, H.Sako, S.Sato, M.Suzuki, T.Chujo, H,Tsuruoka, Y.Miake and PHENIX Collaboration

JPS meeting at Niigata UniversitySeptember 23, 2000

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]2

PHENIX-TOFDevice for Hadron PID

• 960 plastic scintillators with 1920 PMT’s• Locate at 5m from the vertex• Acceptance : driven by HBT and meson

= 40o, = 45o, ~1/3 Sr

Slat: Plastic scintillator w. 2 PMT’sPanel: 96 slats

385cm

200cm

200cm

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]3

Basic Design

• Scintillator: Bicron BC404– decay constant : 1.8 ns

– attenuation length : 160cm

• PMT : Hamamatsu R3478S– rise time : 1.3 ns

– transit time : 14 0.36 ns

• HV Bleeder with chip resisters

PMT

light

light

vtt

x

vltt

t

2

/2

21

210

),( 0 xt

)exp(

/

01

01

x

aa

vxtt light

TimingPulse Height

)exp(

/)(

02

02

xl

aa

vxltt light

{

{{

2)

2()

2(

2)

2()

2(

12221

122210

tvttvx

tttt

lightlight

80 ps

1.3 cm

Scintillator:1.5x1.5x64cm

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]4

Structure

(Lucite)

• Honeycomb Board– Rigid structure with “no mass”

Carbon Fiber Sheet

HoneycombStructure(Paper)

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]5

TOF-FEE

• Custom made chips of TVC+AMU and QVC+AMU– Overall timing resolution of <25 ps

– First pipeline TDC with high resolution.

• Use of Analog memory Unit.

PMT inputslemo

DiscriminattorSub-board

TVC+AMU chip4ch/chip

FEE board16ch/board8layers PC

Block Diagram of FEE

Shaper QVC/AMU

LeadingEdgeDiscr.

TVC/AMU

12bitADC

DAC

FormatBuffer

12bitADC

PMT

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]6

TOF Performance at CERN-WA98

~ 85ps

Time-of-Flight [ns]

Used high momentum TOF resolution for all 500 slats

(1996)

• 5 panels of TOF tested at CERN-WA98.• Overall TOF resolution of < 85ps obtained.

TOF PID Capability at RHIC-PHENIX

Time Resolution: ~ 85 ps / K separation to 2.4 GeV/cK / p,p separation to 4.0 GeV/c

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]7

Construction at Tsukuba (1996-1998)

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]8

Construction at BNL (1998-1999)

• PMT installation• Cable Assemble• Signal Check

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]9

Installation in PHENIX(August 1999)

• All 10 panels were installed.

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]10

First Collisions at PHENIX(6/15/2000)

Number of TOF hits

Occupancy 10%

• The event display shows the fired slats of TOF

• TOF occupancy is less than 10%.

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]11

Year-1 Operation: Zero-field RunTOF Calibration

• Rough calibration parameters obtained. [~100ps level]

– T0 value and Z-vertex information from BBC.

– NO tracking information used yet. (To be done)

– Timing offset, Position offset and Gain Correction

Time offset

y position offset

t = 5 nsec~ length of scinti. 64cm

• BBC Z vertex (-40 < z < 40 cm) are required• L : straight path ( from z-vertex TOF hit position with retracted geometry)• Including BBC Coins, ZDC coins, BBC&ZDC trigger

Calibration conditionCalibration condition

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]12

Track matching and TOF intrinsic timing resolution

• TOF-TEC = 2cm:

– Corresponding timing resolution is 120 ps.

– Consistent with TOF intrinsic timing resolution of 120ps operated without slewing correction.

TIME ~ 120 ps

position ~ 2cm

TECPC3TOF

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]13

Particle Identification

• We can see clear ,K,p separation

• No slewing correction• No final timing adjustment

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]14

Summary

• TOF is working in the first RHIC operating year.

• TOF intrinsic timing resolution is 120 ps fromTEC/TOF matching without slewing correction.

• TOF and Tracking chambers demonstrated clear separation of charged hadrons (,K,p) at Au+Au sqrt(s) = 130 AGeV collision.

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]15

TOF resolution

• Select High-momentum pion.• Current Time of Flight resolution is ~170ps.

– BBC, TOF, Tracking Chamber

• No slewing correction yet.• No final adjustment of relative timing offset yet.• Flight path length need to be tuned.

~ 170 ps

Spare

JPS '00 @Niigata Univ. Sep. 23, 2000

Akio Kiyomichi [Univ. of Tsukuba]16

Operation at PHENIX year1

West East

PbSc

PbSc

PbSc

PbSc

Install in summer 2000

Detector instrumented

Pc1Pc1

RICH RICH

TEC

ToF

PbSc

PbSc

PbGl

PbGl

DCDC

Pc 3 Detector installed

Pc2

Pc3

MVD

• first collision 6/15 ~ end of run 9/4 • Charged Hadron PID by

– Tracking Chamber (DC, PC, TEC)

– Start counter(BBC), stop counter(TOF)

Spare