Commissioning and running of sPHENIX

[Stefan Bathe <stefan.bathe AT baruch.cuny.edu>]

Minutes shift change 2023-05-20

general
—————
- store length limited to 3 h until stochastic cooling commissioned, 
hopefully early next week
- beams much cleaner now than last night, also low rate makes it hard to 
commission MBD trigger ==> moved on from 6x6 bunches to 12x12 — 56x56 
depending on trigger needs
  - e.g. did 56x56 last night b/c of need to take clock triggers for reference

Plan
- 1st priority:  continue MBD trigger commissioning
- 2nd priority:  taking data with calorimeters and timing them in
- goal:  by mid-week:  turn on TPC and TPOT and run in big partition

evening (Sasha)
- not productive
- 6x6 store in beginning
- asked to go to higher number
  - said difficult to go from 6 to 56, so they did 12 first, took 30 minutes 
between stores
  - one hour, then lost
- tried 56, but unsuccessful

night (Brett)
- productive
- lots of people around
- 2am long store:  work on MBD and Lvl1
- then calorimeter people
- 6am new store

Day (Ben)
- calo team working
- 9:30 beam dumped, PS issues, new fill at 1:00pm
  - calo expert had trouble reading data, now solved
- 3:20pm STAR magnet tripped, beam lost
- humidity at alarm threshold of 50 %—>possibly one air handler not 
working—>call MCR

MBD (Mickey)
- up all night working on 2:00am store
- in first store:   could take data:  Ll1 guys (Jaebeom, Dan) working on 
trigger
  - analyzing data
- not quite properly timed in:  probably 5-10 ns off
- 6:00am store:  shift in time:  now know that was b/c of rev tic not working
- rebooted GTM
  - couldn’t take data anymore afterwards
  - now can take data again

HCAL (Oliver) (see slides)
- bias current fluctuations are correlated with ZDC singles counter: 
effectively serves as junk monitor
  - no fluctuations last night:  clean beam
- bias dark current increase plateaued after getting better beams
- Jamie:  oHCAl?  neutrons
  Jin:  MeV neutrons different
  - oHCal also saw fluctuations, but much smaller increase in dark current
- first look at trying to time in HCal:  from 6:00am store (MBD not timed 
in), normal gain
- Jamie:  dead for four in Gl1?  Maybe.
  - Martin:  some value in, but not configurable at this point

EMCal (John)
- setting up code for mapping test
- asked for permission to turn on bias

TPOT (Hugo) see slides
- gas since yesterday
- this morning started applying bias between stores (3 h this morning)
- all chambers on
- 3 out of 60 channels problematic right now
- might need access to investigate
- will investigate noise with HV on
- tomorrow will run one channel with beam

TPC (Jin)
* After GTM work, recovered GTM link on all TPC sectors and 98% of the FEEs. 
Shift crew was kept in the loop during GTM usage.
* First pedestal run with the presence of beam. Being analyzed by Jennifer
* While GTM in local mode, continued opportunistic work to stress test 
double-endpoint firmware
* Mass deployment is ready when opportunistic moment when GTM in local mode. 
Martin is also close to ready for the corresponding RCDAQ plugin
- Hugo:  also deploy to TPOT
* 10% of the FEE links dropped out in around the midnight of May 17, 18, 19; 
but we did not experience much drop last night, May-20, which is interesting

INTT (Joseph)
- online monitoring development
- one thermistor misbehaving
  - elog entry (readout chain, not on actual detector)

MVTX (Jo)
- firmware development
- Ming:  John H installed background monitor:  how clean is beam?
  - John:  didn’t see large excursions, would need messy fill to tell

sEPD (Rosi)
- nothing

DAQ (Martin)
- upgraded GTM firmware v32->v35
  - L1 delay back (1/6 of beam clock 17.7 ns)
  - now have fiducial tick
    - GTM remains stopped until bunch 0 flies by
      - abort gap
      - also 56 relative to 9 MHz
      - tested:  pulled out fiducial, started GTM, remained stopped, plugged 
in, GTM started
- want to be more diligent about actual beam clock
  - will only ever go up
  - made algorithm (see elog entry)
- GTM:  green light:  locked to beam clock:  now register that tells you that 
(firmware upgrade)
- also way to read busy register back (lowest row of LEDs):  can see stuck 
busy
- MBD read-out?  should be no problem:  Martin will take a look
  - Mickey:  read-out working again
- wants to see data with HCal and EMCal when MBD is timed in

Trigger (Dan)
- spend a lot of time reading out MBD with lemo coincidence trigger
  - tried to include vertex trigger, didn’t work well
  - suspect timing issue in N or S
  - developing tools to debug
  - still background mostly in North
- John:  does laser satisfy vertex cut trigger?
- Dan:  no
- Jamie:  vertex distribution? Can Mickey or Abdul look offline with hit 
coincidence
  - Mickey:  maybe off by one clock tick:  sample jumps around
  - laser:  north arrives few ns later

ZDC (John)
- need to take more data with scope (manual operation)—> Ejorp
- for the time being keep stable

Gunther:  sPHENIX magnet temperature?
- Kin:  sensors not sensitive at high temperature

Higher humidity in IR:  alarms going off a lot!
- 
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Stefan Bathe
Professor of Physics
Baruch College, CUNY
and RIKEN Visiting Scientist

Baruch:                                     BNL:
17 Lexington Ave                      Bldg. 510
office 940                                  office 2-229
phone 646-660-6272                phone 631-344-8490
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