1 BNL report ～ the history of Run7 start up ～ Yoshihide Nakamiya

2 BBC hardware work Interlock test - one ADAM module was not worked -> replace it to a new module - one thermocouple broke (S2-4) -> will fix after run7 External charge scan - Adc conversion factor (BbcCalib.adc) - find one Adc to lost linearity (Adc[72]) -> replace QVC ＋ ADC Internal charge & timing scan - Tdc conversion factor (BbcCalib.tdc0 & tdc1) - one of test pulse injector was not worked (Adc[85]) -> replace discriminator for Tdc0&Tdc1 - Adc[126] was not worked properly -> replace QVC ＋ ADC for Adc[126] Measurement of noise rate - a few thousand Hz at most (th = 30 mV)

3 Interlock test ［結果］ ZOOM 交換した ADAM ⇒ Fixed ！ 壊れている熱電対 ⇒ run7 の後に修理

4 External charge scan ~ Before replacement ~ ~ After replacement ~ We got proper gain curve for Adc[72] after replacement of two daughter cards (QVC+ADC).

5 Internal charge & timing scan ~ Before replacement ~ ~ After replacement ~  Adc[85] was fixed after replacement of discriminators Tdc0&Tdc1).  Adc[126] was fixed after replacement of two daughter cards (QVC+ADC).

6 Calibrations and Time-in Calibrations and Time-in Time-in - Adjust global timing offset ⇒ position delay : 170 fine delay (ch 7) : 60 Pedestal scan - Adc pedestal (BbcCalib.pedstal) HV optimization - magnetic field off ⇒ Run7/070323/opHV_run7_bon_ pdf - magnetic field on ⇒ Run7/070402/opHV_run7_boff_ pdf Gain calibration - PMT gain (BbcCalib.pmtgain) Slewing calibration - slewing parameter (BbcCalib.slewpar0&slewpar1) Update LUT & Data Base

7 Global timing offset was adjusted on v124. Collision events are in the middle of Tdc window. V124 Blue Beam Sync -position delay : 170 -fine delay (ch 7) : 60 Time in

8 pedestal was extrapolated by using gain curve as a function of threshold. run list ========================== Threshold of Tdc0 run # ========================== 5mV run mv run mv run mv run mv run ========================== Pedestal scan

9 BBC play a role of not only trigger but centrality determination. We have to optimize HV to satisfy both requirements. 1) Trigger : MIP peaks must not be cut off by threshold since BBC play a role as trigger. 2) Centrality : We must assure linearity of Centrality. We need to pay attention to overflow of Adc under high multiplicity environment like Au+Au collision. I consider these criteria, especially about PMTs which belongs to the inner ring. HV optimization

10 We optimized HV for B ON. Tdc<2600 Isolation cut HV was optimized ~30 V decrease overflow Tdc<2600 Isolation cut Run Run Tdc<2600 HV optimization : B ON

11 HV optimization : B OFF We optimized HV for B OFF. Tdc<2600 Isolation cut Tdc<2600 Run

12 - tdc0 < isolation cut gain calibration was done. Gain calibation Run (B ON) - tdc0 < isolation cut Run (B OFF)

13 slewing calibration was done. Slewing correction Slewing calibarion Run (B ON) Slewing correction Run (B OFF)

14  LUT : We made LUT ⇒ need z offset from DC guys to finalize it.  DB : version 4001 & 4002 were updated ⇒ need z offset from DC guys to finalize it. LUT and DataBase We are waiting for getting z offset calculated by DC&PC.

15 other problems, solutions, remaining tasks other problems, solutions, remaining tasks Laser offset calculation HV mainframe 16 - problem 1 : HV module was tripped - problem 2 : HV mainframe was tripped ⇒ 1) fix 5 fans since 5 fans were not worked 2) replace the HV mainframe 16 Remaining tasks - LUT will be updated (the final version) - Data Base will be updated (ver 4001, ver4002) ⇒ We are waiting for getting z offset calculated by DC&PC in order to finalize calibrations

16 Laser offset calculation Laser offset calculation The special connector were attached in laser fiber of North-bottom. -Laser signal could get delayed. -Laser intensity could decrease.

17 Before correction Affter correction Laser offset calculation Laser offset calculation - Delay depended on laser intensity were automatically fixed by slewing correction - Delay by connection of the connector were fixed by manually as shown above.

18 Laser offset calculation Laser offset calculation Black : before correction Red : after correction We calculated Zvertex offset by laser after corrected systematical delay of North-Bottom.

19 1) HV became Disable. for HV_BB_N-1 & HV_BB_N-1 2) Status indicator shows.. HV_BB_N-1 : 10 HV_BB_N-2 : 40 **status 10 means “Trip -- Violation of supply limits” I'm not sure for status 40 HV mainframe 16 : problem 1 HV mainframe 16 : problem 1

20 1) HV mainframe looks like OFF but actually ON. 2) Measured voltage went to 0V. But HV is “Enable” for HV_BB_N-1 & HV_BB_N-1 HV mainframe 16 : problem 2 HV mainframe 16 : problem 2

21 HV mainframe 16 : Solutions? HV mainframe 16 : Solutions? N4 N3 Slot 0 Slot Slot 11.. N2 N1 0 1  Cable N1 and N2 are separated. ⇒ problem 1 was disappeared  Fix fans on the HV crate since 5 fans (total 12 fans) broke  HV mainframe 16 was replaced ⇒ problem 2 is not seen so far

22 Remaining tasks Remaining tasks  LUT will be updated as the final version  Data Base will be updated (ver 4001, ver4002) We are waiting that DC guy’s work has finished for the final update.