1. 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

2. TOF Performance ２ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001  ~ 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. ３ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001 1.Time offset 2.Slewing parameter 3.Y position offset 4.Light velocity in scint. 5.Energy loss conversion factor 6.Time conversion factor 7.Charge conversion factor 8.TVC/QVC pedestal 9.Global Time offset ( still 0 value ) New Calibration Parameter Dec, 2000 1.Time offset 2.Slewing parameter 3.Y position offset 4.Light velocity in scint. 5.Energy loss conversion factor 6.Time conversion factor 7.Charge conversion factor 8.TVC/QVC pedestal 9.Global Time offset Aug, 2001 By Akio Kiyomichi 9 TOF parameter set BBC parameter set Checked Run dependence By Takashi Hachiya BBC parameter set No Run dependence (Univ. of Hiroshima) 9 TOF parameter set

4. ４ Example. Slewing Correction Update Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001 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] Timing[ns] 6cm 64cm Old （ DSTv03 ） New （ DSTv05 ） |Track_projection - slat_center| <3cm Akio Kiyomichi Analysis meeting@BNL Aug 2 2001

5. ５ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001 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| -100cm –(panel 3 or 4) Year-1 Time-of-flight resolution < 100ps. Momentum [GeV/c] Timing[ns] Akio Kiyomichi Analysis meeting@BNL Aug 2 2001

6. Another Cause worsen resolution ６ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001 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]

7. Panel 3or4, Run#10758-11775 Panel 3or4, Run#11011-11775 Panel 1or3or4, Run#10758-11775 Panel 1or3or4, Run#11011-11775

8. No Cross TalkCross Talk Clean Hit Only < 2 Hits

9. 37m Cable + FIFO (PHENIX) or NONE(WA98) ７ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001 TOF FEM NorthSouth BBC TM FIFO ① BBC TM ======================== ⇒ TOF FEM(N) ② BBC TM ⇒ TOF(S)side====== ⇒ BBC side ⇒ TOF FEM(N) ③ BBC TM ⇒ TOF(S)side ⇒ FIFO ⇒ BBC side ⇒ TOF FEM(N) ① ② ③ σ ～ 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.

10. The Jitter between TOF and BBC ８ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001

11. Jitter ９ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001

12. １０ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001 Year-1 Year-2 ~1500ch~ 2200ch 20nsec delay cable problem

13. Appendix Online Monitoring By Kuroki １１ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001

14. ５．まとめ １２ Yonsei – Tsukuba Workshop ／ Hiroshi Tsuruoka ／ Aug 22 2001