Difference between revisions of "BCAL Reconstruction Issues"
From GlueXWiki
| Line 1: | Line 1: | ||
| − | + | # '''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 |
*** 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 | ||
| Line 10: | Line 10: | ||
** Very low energy ADC hits coming from mcsmear | ** Very low energy ADC hits coming from mcsmear | ||
** Short attenuation length | ** Short attenuation length | ||
| − | + | # 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) | |
** 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 | |
** 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? | ||
| Line 31: | Line 31: | ||
*** 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 | |
** 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) |
Revision as of 15:40, 13 January 2015
- 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
- fADC timing:
- 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?
- 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?
- 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)
- Use only timing information from fADCs?
- 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)
