The V0 detector in ALICE

 

 
Purpose :

  The V0 detector has been proposed ALICE/00-30 in year 2000. It is made of two arrays of scintillator counters set on both sides of the ALICE interaction point, and called V0L and V0R respectively. The V0R counter will be located right upstream of the dimuon arm absorber and cover the spectrometer acceptance while the V0L counter will be located at around 3.5 m away from the collision vertex, on the other side.

It is designed to provide :
  • minimum bias trigger for central detectors,
  • triggers on centrality in Pb-Pb mode,
  • multiplicity information,
  • luminosity control,
  • validation of dimuon triggers and trigger background remediation in p-p mode.

    •   The responsabilities in design, construction, assembly, and operation of the V0 detector have been shared between Lyon and Mexico groups.

     
    Detector description in the Aliroot package :

     

    The V0 detector is described in Aliroot with the segmentation shown in the figure given above. The scintillators are now 0.7 cm thick. Hits are defined (see AliVZEROhit.h) and written in the Hit Tree whenever a track exits the sensitive volume or stops inside.
    You may create a VZERO object by using the AliVZEROv2 class in the configuration file Config.C :

      Int_t     iVZERO = 1;

      if (iVZERO){
    AliVZERO *VZERO = new AliVZEROv2("VZERO", "normal VZERO"); }

     
    ROOT views of V0R :

     

     

     
    Return to previous page

     

    Comments to Brigitte Cheynis
    Last changes on the 23rd of january, 2003.