Difference between revisions of "BCAL Reconstruction Issues"

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# '''Simulation (mcsmear)'''
 
# '''Simulation (mcsmear)'''
** fADC timing:  
+
#* fADC timing: Resolution is too poor
*** Resolution is too poor
+
#* mcsmear doesn't seem to smear data enough
** mcsmear doesn't seem to smear data enough
+
#** TDC timing resolution is too good
*** TDC timing resolution is too good
+
#** single photo-electron peaks in energy spectrum
*** single photo-electron peaks in energy spectrum
+
#* spikes in time histogram at low energy
** spikes in time histogram at low energy
+
#* max ADC amplitude (12 bits?)
** max ADC amplitude (12 bits?)
+
#* Sampling fluctuations not applied on per-particle basis
** Sampling fluctuations not applied on per-particle basis
+
#* Very low energy ADC hits coming from mcsmear
** Very low energy ADC hits coming from mcsmear
+
#* Short attenuation length
** Short attenuation length
+
 
# Timewalk corrections
 
# Timewalk corrections
** Establish procedure for doing these corrections based on simulated data (how closely should this match the correction procedure for real data?)
+
#* Establish procedure for doing these corrections based on simulated data (how closely should this match the correction procedure for real data?)
** Determine form of timewalk corrections
+
#* Determine form of timewalk corrections
** What if we have TDC info only on one end?
+
#* What if we have TDC info only on one end?
 
# DBCALPoint (reconstructing E,z,t from double-ended hit)
 
# DBCALPoint (reconstructing E,z,t from double-ended hit)
** When determining energy, give more weight to higher energy hit? (also in averaging time?)
+
#* When determining energy, give more weight to higher energy hit? (also in averaging time?)
** Best way to determine sigma_z?
+
#* Best way to determine sigma_z?
** How to deal with multiple hits in same channel?
+
#* How to deal with multiple hits in same channel?
 
# Clustering
 
# Clustering
** Use only timing information from fADCs?
+
#* Use only timing information from fADCs?
*** If we use TDC info also, we need to appropriately make use of the different timing errors of different hits
+
#** If we use TDC info also, we need to appropriately make use of the different timing errors of different hits
** Split clusters based on time
+
#* Split clusters based on time
** Determining cluster properties (E, x, y, z, t)
+
#* Determining cluster properties (E, x, y, z, t)
** How to average cell-by-cell position to get cluster position
+
#* How to average cell-by-cell position to get cluster position
*** Weight averages by...? E? E^2? 1/sigma^2?
+
#** Weight averages by...? E? E^2? 1/sigma^2?
*** Average rectangular coordinates? Cylindrical? Spherical?
+
#** Average rectangular coordinates? Cylindrical? Spherical?
** Energy corrections (z-dependent, non-linear)
+
#* Energy corrections (z-dependent, non-linear)
*** Is current scheme good enough?
+
#** Is current scheme good enough?
*** If so, write a plugin to automate this process.
+
#** If so, write a plugin to automate this process.
*** Need extra special treatment of ends of calorimeter?
+
#** Need extra special treatment of ends of calorimeter?
** How to determine errors (and correlations) on cluster properties (important for kinematic fitting)
+
#* How to determine errors (and correlations) on cluster properties (important for kinematic fitting)
 
# Matching with tracks
 
# Matching with tracks
** How to determine if cluster matches track
+
#* How to determine if cluster matches track
** How to determine TOF if more than one matching cluster
+
#* How to determine TOF if more than one matching cluster
*** This is a minor issue since very few (none?) will have >1 match
+
#** This is a minor issue since very few (none?) will have >1 match
** Need to match in third dimension (R)
+
#* Need to match in third dimension (R)

Revision as of 15:41, 13 January 2015

  1. Simulation (mcsmear)
    • fADC timing: Resolution is too poor
    • mcsmear doesn't seem to smear data enough
      • TDC timing resolution is too good
      • single photo-electron peaks in energy spectrum
    • spikes in time histogram at low energy
    • max ADC amplitude (12 bits?)
    • Sampling fluctuations not applied on per-particle basis
    • Very low energy ADC hits coming from mcsmear
    • Short attenuation length
  2. Timewalk corrections
    • Establish procedure for doing these corrections based on simulated data (how closely should this match the correction procedure for real data?)
    • Determine form of timewalk corrections
    • What if we have TDC info only on one end?
  3. DBCALPoint (reconstructing E,z,t from double-ended hit)
    • When determining energy, give more weight to higher energy hit? (also in averaging time?)
    • Best way to determine sigma_z?
    • How to deal with multiple hits in same channel?
  4. Clustering
    • Use only timing information from fADCs?
      • If we use TDC info also, we need to appropriately make use of the different timing errors of different hits
    • Split clusters based on time
    • Determining cluster properties (E, x, y, z, t)
    • How to average cell-by-cell position to get cluster position
      • Weight averages by...? E? E^2? 1/sigma^2?
      • Average rectangular coordinates? Cylindrical? Spherical?
    • Energy corrections (z-dependent, non-linear)
      • Is current scheme good enough?
      • If so, write a plugin to automate this process.
      • Need extra special treatment of ends of calorimeter?
    • How to determine errors (and correlations) on cluster properties (important for kinematic fitting)
  5. Matching with tracks
    • How to determine if cluster matches track
    • How to determine TOF if more than one matching cluster
      • This is a minor issue since very few (none?) will have >1 match
    • Need to match in third dimension (R)