1. Readiness of Forward Muon Arms for W Detection Itaru Nakagawa For the PHENIX Muon Trigger Upgrade Collaboration 1

2. 2 2 1.Muon Tracking Chambers – 3 stations of Cathode strip chambers – Each station has multiple planes for redundancy – Slow read out -> No trigger 2.Muon Identifier – 5 layers of Iarocci tubes in x and y – 80 cm of steel plate absorber (total) – Provides trigger p  > 2 GeV St#1 St#2 St#3 MuTr Same configuration in South MuID   B Current Muon System

3. 3 Observed in Run9 pp B ,k  fake High P T  Study done by Yoshinori Fukao (RIKEN)

4. 4 Efficiency Measurement with Cosmic Ray cosmic High Efficiency under Clean Circumstance! High Efficiency under Clean Circumstance! Study done by Yoshinori Fukao (RIKEN)

5. MuTRG System Run09 performance 5 MuID Algorithm Track Matching w/ MuID Timing cut w/ RPC Track Matching w/ RPC Neutron Backgrounds Yoshimitsu Imazu’s Talk etc.. MuID Algorithm Track Matching w/ MuID Timing cut w/ RPC Track Matching w/ RPC Neutron Backgrounds Yoshimitsu Imazu’s Talk etc..  MuTrg-FEE x MuID Study done by Yoshinori Fukao (RIKEN)

6. 6 Rate Dependence of MuID Rejection Power Can RPC substitute MuID? Does RPC give better Rejection Power?

7. 7 Road Map to Run11 Production Run MuTRG RPC3 Run11 RPC3 absorber

8. Completed Installation of Absorbers 8 North Station-1 New Hadron Absorber New Hadron Absorber North South 35cm thick SUS310 (2 interaction Length)

9. 9 Final Muon Trigger Configuration MuTRG RPC3 Run12 RPC3 absorber RPC1

10. MuTr X-Talk 10

11. MuTr Cross Talk 11 HV (1800 V) 1 M  Anode wire 1 M  100 pF.... Cathode strips (96 strip) ~0.1 pF/strip Rise time of anode signal ~ 10 nsec Removed to reduce HV trips Anode Readout 100mV 3V3V 3V3V Serious Issue for Big Pulse Pointed out by Tsutomu Mibe@KEK Decap Doesn’t exist.

12. 12 ADC MIP Event Display of ADC Distribution Strip Gap 1 Stereo Gap 2 Stereo Gap 3 Stereo Gap 1 NonStereo Gap 2 NonStereo Gap 3 NonStereo Origin of Big Pulse -> Neutrons?

13. Can be serious issue at high rate 13 x2 (Run 11?)x5 (design) Current set up Recap (1/10? cross talk) Luminosity Rate per strip (kHz) Run 9, 500 GeV data 10  s Pileup at 100kHz

14. Solution 14 HV (1800 V) 1 M  Anode wire 100 pF.... Cathode strips (96 strip) ~0.1 pF/strip Rise time of anode signal ~ 10 nsec R<<1M  1 M  Additional Circuit to let anode current escape to ground.

15. Pads for surface mount capacitors Left over Solder + Coating Pads for surface mount capacitors Left over Solder + Coating To Anode Wire MuTr Station-3 Anode Card Capacitor (Removed) 15

16. North Station-3 Anode Gap 16 25mm 28mm Geometrical Constraint Anode cards are only accessible from their back. Front pattern can only be visible using an inspection mirror.

17. Recap Clamp Prototypes 17 R&D by Yoshinori Fukao (RIKEN) Yoshimitsu Imazu (RIKEN) Kentaro Watanabe (Rikkyo)

18. Effect of Recap 18

19. Test Bench Setup 90Sr Source Anode wire 19 Strip #22 w/ and w/o Clamp

20. Comparison w/.vs w/o Terminator 22 27 17 Trigger w/o Clamp Strip# 20 22 27 17 w/ Clamp Trigger w/o Clamp

21. Comparison w/.vs w/o Clamp w/o Clamp With Clamp Strip Number Average ADC [channel] Conductive Rubber 21

22. Neutron Absorber 22

23. 23 The full muon arm again Only 1/20 of all PYTHIA events Only MuTr St1 Y-scale is from old macro Only neutrons from upstream of St1  Neutrons in St1  Current setup  SS310 absorber  +SWX207HD5  Only SWX207

24. Thermal Neutron Origin of Big Pulse Thermal Neutron Absorber Thermal Neutronphoton AbsorberBorated Poly 2.5cmPb 1cm + Fe 1cm Attenuation~10 -2 ~5x10 -2 478keV B 25mm Pb 1cm MuTr 25meV neutron (e,  ) Fe 1cm 24

25. Summary High Momentum Muon Trigger (MuTrig-FEE & RPC3) is to be commissioned in Run11 Sufficient Rejection Power can be achieved, but trade off of efficiency. 99% Efficiency with Cosmic at High P T Thermal Neutron is suspect degrades MuTr performance – Neutron Absorber Partial Install – Recapacitation Clamp Prototypes to be tested in Run11 25

26. Backup Slides 26

27. Towards Successful Installation 27

28. 28 Fiber Scope Alignment Spacer determines Transverse direction within ~ 300  m. Spacer determines Transverse direction within ~ 300  m. Possible misalignment can be found by visual inspection using a fiber scope Possible misalignment can be found by visual inspection using a fiber scope Fiber scope shot

29. Electrical Contact 29 Readout socket Readout Board Electrical Contact will be confirmed by measuring Voltage using temporary readout tool. Electrical Contact will be confirmed by measuring Voltage using temporary readout tool. To be removed after the measurement.

30. Installation Proposal Single Pin Probe x 20 4 Pin Probes x 20 Conductive Rubber x 20 30 To be installed North Bottom Octants

31. ClampCoatingMax CurrentAverage Current w/ow/<1uA w/w/o>100uA Tripped after 2 min. w/ 1uA w/w/o>100uA Tripped after 1min. w/ 2uA 31 Extreme Breathing Test HV=1900V Duration 2min

32. MuTr Station-3 32

33. Recapacitation (Station-3) Capacitor はすべて取り外し済み。 Station-3 Chamber を取り出すの実質的に難しい。 簡易的に取り付けられるクリップでグラウンドに落とす。 Capacitor はすべて取り外し済み。 Station-3 Chamber を取り出すの実質的に難しい。 簡易的に取り付けられるクリップでグラウンドに落とす。 33

34. Coating Anode Card Parylene C Print Kote remover Takes time, but removable 化学的に溶かすには 175 ℃でクロロ ナフタレンに反応して溶解（１時 間以上）。 事実上ムリ。 De-Capacitation( コンデンサーの取り外し）の際にパリレンが溶けてるのでは？ 34

35. DAQ による測定 ADC>1000ch 以上の事象 ADC>1000 以上の大きなパルスを 観測したとき、周辺のストリップに は逆電価のシグナルが観測される。 ADC>1000 以上の大きなパルスを 観測したとき、周辺のストリップに は逆電価のシグナルが観測される。 …,13,1431,32,… …21,22,23… 90Sr 線源 ストリップ番号 ADC [channel] Anode wire を共有して いない Anode wire を共有して いない Anode wire を共有して いない Anode wire を共有して いない 線源直下のストリップ 35

36. 36 Low energy neutrons Low energies Fluctuation before SWX needs investigation Suppression of very low energies might depend on input neutrons behind SWX207HD5 before SWX207HD5