yonsei – tsukuba workshop ／ hiroshi tsuruoka ／ aug 22 2001

Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001

１

Current Status of TOF Analysis

１． PHENIX実験とは

２．なぜ新たな検出器が必要か？

３． Time Zero Counter の設計

４．テスト実験（ KEK）

５．まとめ

TOF Performance

２

　


~ 85ps

CERN WA98 (1996)

σ<110ps

PHENIX TOF (Dec 2000)Tsukuba-Yonsei Workshop

By Akio Kiyomichi

We want to understand the contents of 110psec time resolution.

New calibration parameter

Another cause

Cable length , FEM jitter

３


1. Time offset2. Slewing parameter 3. Y position offset4. Light velocity in scint.5. Energy loss conversion factor6. Time conversion factor 7. Charge conversion factor8. TVC/QVC pedestal9. Global Time offset ( still 0 value )

New Calibration Parameter

Dec , 2000

1. Time offset2. Slewing parameter 3. Y position offset4. Light velocity in scint.5. Energy loss conversion factor6. Time conversion factor 7. Charge conversion factor8. TVC/QVC pedestal9. Global Time offset

Aug , 2001

By Akio Kiyomichi

9 TOF parameter set

BBC parameter setChecked Run dependence

By Takashi Hachiya

BBC parameter set

No Run dependence

(Univ. of Hiroshima)

9 TOF parameter set

４

Example. Slewing Correction Update


• Problem in v03:

– Slewing curve is weak by effect of attenuation.

• for DSTv05

– Select hit region on scintillator.

• 　– To compensate for low statistics, add 32 PMTs with

• PMT Gain correction & Timing adjustment

PMT

QVC[ch]Spread

Fitting function: y = A + B/sqrt(x)

QVC[ch]

Tim

ing[

ns]

Tim

ing[

ns]

6cm

64cm

Old 　（ DSTv03 ）

New　（ DSTv05）

|Track_projection - slat_center| <3cm

Akio Kiyomichi Analysis meeting@BNL Aug 2 2001

５


TOF Performance For Year-1

used data :

run11011 - 11775

cut criteria :

• centrality 0-5% [cent == 0]

• dch_quality == 23 or 31

• eloss > 2MeV

• dR < 2 sigma (matching cut)

• |tofz|<50cm && tofy>-100cm

– (panel 3 or 4)

Year-1 Time-of-flight resolution < 100ps.

Momentum [GeV/c]

Tim

ing[

ns]

Akio Kiyomichi Analysis meeting@BNL Aug 2 2001

Another Cause worsen resolution

６


Cross talk on FEM board

several hits on slat

cross talk !

clean hit !

several hits

ALL 501event 96 ± 5 ps

No cross talk

462event 97 ± 5 ps

Clean hit only

341event 89 ± 7 ps

A cut of clean hit only is effective !

Cut Criteria : Run11011-11775,cent[0-5%],Q=23or31,eloss>2MeV,dR<2sigma,1.4<p<1.8MeV,TOF Panel 1,3and4

TOF – L／（ c・ β） [nsec]

Panel 3or4 , Run#10758-11775

Panel 3or4 , Run#11011-11775

Panel 1or3or4 , Run#10758-11775

Panel 1or3or4 , Run#11011-11775

No Cross Talk Cross Talk

Clean Hit Only < 2 Hits

37m Cable + FIFO (PHENIX) or NONE(WA98)

７


TOF FEM TOF FEM

North South

BBC TM

FIFO

①BBC TM ======================== TOF FEM(N)⇒

②BBC TM⇒TOF(S)side======⇒BBC side TOF FEM(N)⇒

③BBC TM⇒TOF(S)side⇒FIFO⇒BBC side TOF FEM(N)⇒

①②

③σ～ 42ps

①　～WA98

②

σ～ 50ps

③　～ PHENIX

σ～ 47ps

TVC[ch]

～ 3300

～ 3000

～ 3270

TVC=3300[ch] is the dynamic range which we can measure a particle of beta=1.

FIFO works as discriminator module.

A 37 meter long cable worse resolution a little.

The Jitter between TOF and BBC

８


Jitter

９


１０


Year-1 Year-2

~1500ch ~ 2200ch

20nsec delay cable problem

Appendix Online Monitoring By Kuroki

１１


５．まとめ

１２


yonsei – tsukuba workshop ／ hiroshi tsuruoka ／ aug 22 2001

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