Home Page of the Trigger Reconstruction Software for the FIRST experiment

This is the home page of the software for the Trigger reconstruction of the FIRST experiment

Data Analysis Team

  • V. Monaco
  • R. Sacchi

Retrieve trigger info from data files

Trigger Pattern

Trigger info is encoded in the TATRdatRaw class/objects. The meaning of the various patterns and the classification of the triggers is explained below in the trigger Output table description. To access it in the WM framework you can use the code snippet from below:

      TATRdatRaw* p_trraw  = 
   (TATRdatRaw*) myn_trraw->GenerateObject();
      
      Int_t i_ntrhit = p_trraw->ntrhit;
      for (Int_t i = 0; i < i_ntrhit; i++) {
   const TATRrawHit* atrHi = p_trraw->Hit(i);

   printf("Pattern:: %lx \n",atrHi->Pattern());
   for(int i=0; i<11; i++) {
     trType[i] = atrHi->Pattern() >> i & 0x1;
   }
      }

Trigger Time

The time of trigger signals is registered as well. Details are encoded in the geomaps/tr_ch.map file
!Trigger channel and TDC board.
T0 47  17
!1--> Mast trig
T1 32  17
!2--> Double SC
T2 33  17
!3--> Tof
T3 34  17
T4 35  17
!5--> Mast trig in kentros TDC
T5 32  16
!6--> Double of SC in kentros TDC
T6 33  16

The timing info stored in the TATR class can be retrieved with:

TATRdatRaw* p_trdatraw  = 
    (TATRdatRaw*) myd_trraw->GenerateObject(); 
TATRrawHit* trraw_hit = p_trdatraw->Hit(0);

  Double_t time_trg_mast = trraw_hit->TrigTime(1); //Master trigger! 
  Double_t time_trg_tof = trraw_hit->TrigTime(2); // SC Timing 
  Double_t time_trg_tof = trraw_hit->TrigTime(3); // Tof Timing 

Trigger informations from root files

The trigger logic was implemented in a Vulom VME board.

List of input triggers provided by the detectors to the Vulom:

  • input 1 : SC (start counter)
  • input 2 : VETO
  • input 3 : TOF-AND (AND of front and back TOF)
  • input 4 : KENTROS
  • input 5 : LAND-Physics
  • input 6 : LAND-Cosmics
  • input 7 : TOF-OR (OR of front and back TOF)

A Fast Trigger/Fast-Clear logic has been locally implemented in the I.R.crate to provide a prompt trigger signal to the I.R. QDCs. The Fast-Clear logic also prevents the propagation of SC, KENTROS and VETO triggers to the Vulom during the dead-time of the Fast-Clear logic itself or during the Dead-Time of the acquisition. Additional inputs were provided to register some information in a scaler

  • input 15 : Fast-Clear pulse from the I.R. (the SC trigger is not accepted and the QDCs of the I.R. are cleared)
  • input 16 : number of SC triggers regardless the Dead-Times

The input triggers are combined in different Logic Matrix Units to provide the following Trigger Outputs:

  • output 1 : SC (physics trigger)
  • output 2 : SC & .not.VETO (physics)
  • output 3 : SC & TOF-AND (physics)
  • output 4 : SC & KENTROS (physics)
  • output 5 : SC & LAND-Physics (physics)
  • output 6 : SC & TOF-OR (physics)
  • output 7 : VETO (physics)
  • output 8 : SC & VETO (physics)
  • output 9 : LAND-Cosmics (calibration trigger)
  • output 10: KENTROS-Cosmics (calibration)
  • output 11: TOF-AND (calibration)

The final Master Trigger is the OR of the accepted triggers.

During data taking, only few Output Triggers were enabled.

A reduction factor is usually applied on calibration or control triggers.

Trigger configurations during the data taking:

run range enabled triggers reduction factors NOTES
127-130 2(SC&.not.VETO) + 4(SC&KENTROS) + 6(SC&TOF-OR) red(2)=2^4  
131 to be checked red(2)=2^4 to be checked
132-175 2(SC&.not.VETO) + 4(SC&KENTROS) + 6(SC&TOF-OR) + 9(LAND-Cosm) red(2)=2^4 red(9)=2^2  
176-179 11(TOF-AND)   TOF cosmics
180 2(SC&.not.VETO) + 4(SC&KENTROS) + 6(SC&TOF-OR) + 9(LAND-Cosm) red(2)=2^4 red(9)=2^2  
181-187 2(SC&.not.VETO) + 4(SC&KENTROS) + 6(SC&TOF-OR) + 9(LAND-Cosm) red(2)=2^4 red(9)=2^3  
188-248 1(SC) + 2(SC&.not.VETO) + 4(SC&KENTROS) + 6(SC&TOF-OR) + 7(VETO) + 9(LAND-Cosm) red(9)=2^3  
249-386 1(SC) + 9(LAND-Cosm) red(9)=2^4  
386-471 1(SC) + 7(VETO) + 9(LAND-Cosm) + 10(KENTROS-cosmics) red(7)=2^5 red(9)=2^4 red(10)=2^3  
471-473 1 + 2 + 3 + 4 + 7 + 9 + 10 red(1)=2^5 red(7)=2^5 red(9)=2^4 red(10)=2^3 trigger tests
474-525 1(SC) + 7(VETO) + 9(LAND-Cosm) + 10(KENTROS-cosmics) red(7)=2^5 red(9)=2^4 red(10)=2^3  

The trigger timings have not been changed during these runs.

Useful trigger/DAQ informations from the root files (WM framework):

  • TAGntuEventInfo::trig (readout trigger type)
    • 1 = physical trigger
    • 2 = calibration trigger

  • TAGntuEventInfo::time (time of the current event in sec)
  • TAGntuEventInfo::evt (event number)

  • TATRrawHit::Pattern() (Trigger pattern - bit (i) is 1 if Output Trigger (i+1) fired)

  • TATRrawHit::GetTrigBefLMU(i) (returns the value of a scaler for input trigger i+1)

Analysis Tasks

-- AlessioSarti - 02 Oct 2011
Topic revision: r6 - 2011-11-09, AlessioSarti
 
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