ECAL Pre-firing

This page gives details about different aspects of the ECAL trigger pre-firing and related studies.

ECAL Pre-firing




Studies to be performed

In order to mark the ECAL Pre-firing studies as complete, we need following four studies.

Measurement of effects using data and emulated TPs.


Measurement using gap flag studies


Measurement using June 2018 time scan data


Measurement using simulation

At this moment most of the information below comes from the email by Kostas.

  • Step 1: Install CMSSW

cmsrel CMSSW_10_3_0_pre5
cd CMSSW_10_3_0_pre5/src 
scram b 


# following line will copy the SimCalorimetry/EcalSimAlgos package from the official installed CMSSW package.  
cp -r $CMSSW_RELEASE_BASE/src/SimCalorimetry/EcalSimAlgos

# We will edit the line number 219 of this file SimCalorimetry/EcalSimAlgos/src/
emacs SimCalorimetry/EcalSimAlgos/src/

# go to line 219 and edit the timing/delay/phase  

 const double tzero = ( shape()->timeToRise()
                          + parameters->timePhase()
                          - 17.0
                          - jitter
                          - BUNCHSPACE*( parameters->binOfMaximum()
                                         - m_phaseShift             ) ) ;

# once the .C file is changed, compile the package. 
scram b -j 4 

# if it compiles fine, we have finished second step. 

Copy of email

Because of the mixing and the perplexed structure of cmsDriver output, I wasn’t able to fully understand in which parts of the python the timephase should be modified (see below*).

At the moment, I think the safest way to inject the delays, is unfortunately to checkout


and modify

adding by hand a line with the desired delay.

Looking at the output of this “manual intervention” for a -17ns delay this has significant effect, in the hits’ energy

but I have no quick way to check the Digi/Pulses. Before asking for MC production, would you Dave or anybody else be able to have a quick look in the corresponding Digis and verify that the delay is in the direction we want ?

I placed 2 files in


produced with CMSSW_10_3_0_pre5 with

  • cmsdriver command ZEE_13TeV_TuneCUETP8M1_cfi --conditions auto:phase1_2018_realistic -n 20 --era Run2_2018 --eventcontent FEVTDEBUG -s GEN,SIM --datatier GEN-SIM --beamspot Realistic25ns13TeVEarly2017Collision --geometry DB:Extended --python --fileout file:step1.root --nThreads 8

and step2 --conditions auto:phase1_2018_realistic -n 100 --era Run2_2018 --eventcontent FEVTDEBUGHLT -s DIGI:pdigi_valid,L1,DIGI2RAW,HLT:@relval2018 --datatier GEN-SIM-DIGI-RAW --geometry DB:Extended --dump_python --python --filein file:step1.root --fileout file:step2.root --nThreads 8

change in C++ code:

const double tzero = ( shape()->timeToRise() + parameters->timePhase() - 17.0 - jitter - BUNCHSPACE*( parameters->binOfMaximum() - m_phaseShift ) ) ;

  • Two test samples have been already generated by Kostas, located at: /afs/

-- RamanKhurana - 2019-07-18

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Topic revision: r1 - 2019-07-18 - RamanKhurana
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