FGT commissioning

2012-01-10 11:00
2012-01-10 12:00
America/New York
Tuesday, 10 January 2012
EVO bridge, at 16:00 (GMT), duration : 01:00

Present: Hal, Anselm, Bernd,Gerard,Ramiro,Will, Jan, Dave U., and Steve G.

 Milestones for FGT comissioning are :  

  1. ***DONE***  demonstarted 90% of channels work before collossions (pedestals are healthy)
  2. ***DONE***  FGT hold 3.6kV w/ ArCo2 gass
  3. demonstarted 90% of channels still work when beam circulates
  4. timing is set
  5. mapping in offline DB is correct
  6. set workig point for pp500 

 

FGT commissioning tasks  ver 2   (time ordered, [M]- denotes a milestone) 

 
------- FEE powered on, STAR DAQ operational ------ 
 
1) setup all control files and demonstarte all GUIs are operational
2a) ped+status table ,  [M1: 90% of APV works & 90% of channels/each APV works]
2b) adjust APV ped in fee , repeat - if needed 
3) access: fix broken hardware
4) HV test w/o beam , N2 gas, 1 day, Bernd, [M2: FGT holds 3.6kV]
5) swap gas , N2-->ArCo2, Bob S. , 1/2 day, just before collisions
------- require collision overnight ---------  
6) HV up/down w/ collisions, 6 days, Bernd+Gerrit
7a) ped+status table , 1 day  [M3: 90%-90% live channels under beam] 
7b)  access: fix broken hardware
------- minB trigger set -----
8)  attempt to catch FGT collision signal during ETOW timing using minB trigger
-------   EHT trigger, possible 3/4 of ETOW HV off to better use avaliable band width ----
10) set timing, 3 data sets taken 2 days apart, 1 week, Jan+Gerard , [M4: timing set]
* set 1 : disperse offsets for groups 5APV (per octant), scan TCD delay to catch collision in some 
* set 2 : adjust all APVs, determine residual corrections per APV
* set 3 : verify signal centered at 2nd time bin for all APV chips
11) re-adjust APV ped
12) verify quadrant mapping, 1 day , few data sets with quadrants HV on/off
13) verify APV mapping, take few data sets with alternative APVs on/off .
--------- regular pp200 physics data taking, many fills  ---------

13) study of FGT working point : multiple data sets, ~2 days per set, considered combinations:

     *gas mix: 70-30 , 90-10 
     * HV set to 3.4, 3.5, 3.6 kV
     * low gain ref data at  low HV with one gas mix
14) verify strip mapping using  large  data sets, needs non-existing software [M5: mapping in DB is correct]

------------ after few weeks of pp200 data taking -------

15) tune APV  params to optimize signal shape,  Criterium:   signal amplitude to noise RMS , no code for that  

16) enable ZS , requires Willie's online monitoring to work, and on-line peds computation (by Tonko's  code?) 

----------- before switch to pp500 ---------

17) chose final working point for FGT HV & gas-mix [M6: pp500 lworking point]

-----------  pp500, take production data: goal prove FGT works ---------

 18) operational L2W algo w/ monitoring , Ross works on it now

 

 

Minutes:

  •  overview of commissioning plan, revision follows (draft schedule in attachment, obsolete), main conclusions:
    • significant # of tasks can and should be accomplished before the first collisions - see green section
      • analysis of ped+stat of one taken already run should proceed now
    • we do not have schedule with dates & names, I'll not give up on this
    • there are 4 people who will be allowed to operate FGT HV are: Benrd,Gerrit,Ross,Ramiro
    • handling of FGT operation in to STAR crew is a very distant idea, the plan is this 4 people will support fgt operation on site as long as it is needed 
    • finding the collision signal in FGT data is perceived as very difficult (shown in red)
      • it is safer to require the EHT trigger (plan A), but also try to see FGT signal with minB trigger during EMC timing scan (very optimistic scenario)
      • FGT deadtime in the early weeks is ~700 us, e.g. 7% dead @ 100 Hz.
      •  may require lower EHT thres and turn of HV for 3/4 of ETOW - need dedictaed trig config & EMC settings
      • deveopement of not existing code fitting time dependence of individual pulses has  been elevated to the top
      • in parallel developement of nonexisting code fitting integrals will be pursued
    • verification of mapping in DB will have 3 phases: quadrant, APV, and strip-level
    • tuning of peds in APV will be done twice: ASAP, and after timing is adjusted
    • not decided what FGT gas pressuer & HV will be set for study of the best working point (days-long data sets in pp200)
      • analysis criteria were discussed: efficiency vs. HV; cluster size; efficiency vs. saturation of cluster energy; MIP signal to pedestal width;
      • with disconnect to avaliable software - there is no code do generate any of those observables nor people to schedule to work on it
    • identified need for software to evaluate signal/noise , needed to tune APV settings
  • the discussion about use of existing vs. developing new code was endless.  People remained faithful to their respective views. In my opinin the comissioning task #16 - enableing ZS for pp500 - requires Willie to finish up the code he started.  Many side benefits justify Willie does it now, not  in a month. 
  • questions from Jan:
    •  access dates  - Bernd will sent a note
    • will FEE be on 24/7 : yes, said Gerard
    • how do we deal with correlated noise : Gerard suspects it is not a big issue, we have ped file taken w/ STAR DAQ and a maker based software to compute sth. Limitted (to 1) possible manopwer. Analysis downgraded in priority, after code for items up to 13 is in hand.
    • when do we switch to ZS mode? G: at the end of pp200.
    • will we ever use  wave form readout mode? G: we do it already. 
  • NOT discuss status of FGT readout based on Willie's plots http://drupal.star.bnl.gov/STAR/node/23008/