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BNL reportBNL report～～ the history of Run7 start upthe history of Run7 start up ～～

Yoshihide Nakamiya

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BBC hardware workBBC 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)

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Interlock testInterlock test

［結果］

ZOOM

交換した ADAM⇒Fixed ！

壊れている熱電対　⇒ run7 の後に修理

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External charge scanExternal 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 scanInternal 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).

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Calibrations and Time-inCalibrations and Time-inTime-in

- Adjust global timing offset ⇒ position delay : 170 　　　　 fine delay (ch 7) : 60

Pedestal scan - Adc pedestal (BbcCalib.pedstal)

HV optimization - magnetic field off ⇒http://www.hepl.hiroshima-u.ac.jp/phx/bnl/pmt/　　　　　 Run7/070323/opHV_run7_bon_070323.pdf - magnetic field on ⇒http://www.hepl.hiroshima-u.ac.jp/phx/bnl/pmt/　　　　 Run7/070402/opHV_run7_boff_070402.pdf

Gain calibration - PMT gain (BbcCalib.pmtgain)

Slewing calibration - slewing parameter (BbcCalib.slewpar0&slewpar1)

Update LUT 　 & 　 Data Base

7Global 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 inTime in

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pedestal was extrapolated by using gain curve pedestal was extrapolated by using gain curve as a function of threshold.as a function of threshold.

run list========================== Threshold of Tdc0 run #========================== 5mV run226402 10mv run226403 20mv run226404 30mv run226405 15mv run226406 ==========================

Pedestal scanPedestal scan

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<HV optimization criteria>

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 optimizationHV optimization

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We optimized HV for B ON.

Tdc<2600

Tdc<2600

Isolation cut

HV was optimized

~30 V decrease

overflow

Tdc<2600

Isolation cut

Run 226332 Run 227016

Tdc<2600

HV optimization : HV optimization : B ONB ON

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HV optimization : HV optimization : B OFFB OFF

We optimized HV for B OFF.

Tdc<2600

Isolation cut

Tdc<2600

Run 227702

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- tdc0 < 2600- isolation cut

gain calibration was done.

Gain calibationGain calibationRun 227016 (B ON)

- tdc0 < 2600- isolation cut

Run 227702 (B OFF)

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slewing calibration was done.

Slewing correction

Slewing calibarionSlewing calibarionRun 227016 (B ON)

Slewing correction

Run 227702 (B OFF)

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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 DataBaseLUT and DataBase

We are waiting for getting z offset calculated by DC&PC.

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other problems, solutions, remaining tasksother 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

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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.

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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.

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Laser offset calculation Laser offset calculation

Black : before correctionRed : after correction

We calculated Zvertex offset by laser after corrected systematical delay of North-Bottom.

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<Symptom 2>

1) HV became Disable. for HV_BB_N-1 & HV_BB_N-1

2) Status indicator shows..

HV_BB_N-1 : 10HV_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

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<Symptom 1>

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

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HV mainframe 16 : Solutions? HV mainframe 16 : Solutions?

N4

N3

Slot 0Slot 1

0

1

Slot 11

. . . .N2

N10

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

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Remaining tasks Remaining tasks

<Remaining tasks>LUT will be updated as the final versionData Base will be updated (ver 4001, ver4002)

We are waiting that DC guy’s work has finished for the final update.