The CALICE trigger system
The CALICE trigger system is changing from year to year, from set-up to set-up. A description of the main trigger components is given below following the naming scheme used in calice_userlib/include/TriggerBits.hh. For each trigger bit a function exists that can be used by the analyzers to check if one determined bit has fired during an event, i.e. isBeamTrigger() returns 1 if kBeamBit==1.
kUnknownBit=0, kBeamBit=1, // defined by the DAQ logic, the pair of triggers or single trigger used as main trig. in data taking (can change at every run) kPedestalBit=2, // random trigger to collect noise events kCosmicsBit=3, // NOT used at test beam, horizontal scintillator coincidence to trigger on cosmics kCalibBit=4, // trigger for LED systems (for AHCAL, TCMT and ScECAL) kVetoBit=5, // digital output of the 20x20cm multiplicity counter on the beam line (the analog output tells the multiplicity of beam particles in one event and is read out from the processor VetoCounter (in 2007/2008 kVeto_20x20Bit was used) kCherenkovBit=6, // first Cherenkov bit (for 2006-2007 CERN this is the only Ch. bit) the meaning is different depending on the pressure and gas type. Generally used to disciminate electrons and pions (e == 1, pi == 0) BUT WATCH OUT FOR EXCEPTIONS!! kSC1_3x3Bit=7, // in 2006 only, pair of 3x3cm scintillator counters kSC2_3x3Bit=8, // in 2006 only kSC1_10x10Bit=9, // in every year, mail trigger coincidence for data taking kSC2_10x10Bit=10, // in every year, mail trigger coincidence for data taking kSC1_100x100Bit=11, // first muon trigger in front of set-up, normally removed from the beamline during data taking kSC2_100x100Bit=12, // second muon trigger in the back of the TCMT, used also as muon tag kSpillBit=13, // delivered from beamline, spill signal in coincidence with the beam to our experiment kCrcOscillatorBit=14, // used for DAQ debugging kExternalPulserBit=15, // used for DAQ debugging kExternalLEDBit=16, // used for LED system debugging kFingerHorizontBit=17, // in 2005 DESY, coincidence of finger counters 3x3mm kFingerVertBit=18, // in 2005 DESY, coincidence of finger counters 3x3mm kVetoULBit=19, // starting 2007, 1x1m veto counter with 20x20cm hole in the middle, real veto for beam halo. kVetoDRBit=20, // starting 2007, the counter is made of 4 parts with 4 PMT readout (Up-Right, Down-Left, ...) kVetoURBit=21, // starting 2007, use as a or of the 4 counters to generate the full veto. kVetoDLBit=22, // starting 2007, kSC1_20x20Bit=23, // same as kVetoBit, different definitions in different years, NOT USED kVeto_20x20Bit=24, // USED in 2007/2008 (same as kVetoBit) kCherenkov2Bit=25, // in 2008 at FNAL, second Cherenkov bit (more details to come...) kGenericBit=31 // DAQ check };
The schematic of the 2008 test beam at FNAL, with trigger position, can be fund here: http://ttfinfo.desy.de/CALICEelog/data/doc/FNAL%20docu/2008-05-13T17:21:19-00.pdf
The schematic of the 2007 test beam at CERN, with trigger position, can be fund here: http://www.pp.rhul.ac.uk/~calice/fab/WWW/dataSummary.htm#nav_beamline