Difference between revisions of "BCAL Calibration"
From GlueXWiki
(→TDC_offsets) |
(→CCDB Tables) |
||
Line 67: | Line 67: | ||
2 column, 1 rows. | 2 column, 1 rows. | ||
This is used in DBCALHit_factory.cc , it is added to the hit time | This is used in DBCALHit_factory.cc , it is added to the hit time | ||
+ | Used to centre the ADC and TDC times at 0 as initial calibration | ||
====ADC_timing_offsets==== | ====ADC_timing_offsets==== | ||
1 col, 1536 row | 1 col, 1536 row | ||
− | + | Used in DBCALHit_factory | |
+ | Used to remove the 4 ns timing offset. | ||
+ | |||
+ | ====TDC_offsets==== | ||
+ | |||
+ | 1 col, 1152 row | ||
+ | Used in DBCALTDCHit_factory , it is subtracted from the hit time. | ||
+ | This is used to remove the 32 ns offset. | ||
+ | |||
+ | ====channel_global_offset==== | ||
+ | |||
+ | 1 col, 768 row | ||
+ | Used in DBCALHit_factory and DBCALTDCHit_factory , it is subtracted from the hit time. | ||
====effective_velocities==== | ====effective_velocities==== | ||
Line 79: | Line 92: | ||
used in DBCALPoint_factory to calculate z and throw away points > 60 cm from BCAL | used in DBCALPoint_factory to calculate z and throw away points > 60 cm from BCAL | ||
used in DBCALPoint to subtract the fiber-propagation-time from the time sum | used in DBCALPoint to subtract the fiber-propagation-time from the time sum | ||
− | |||
− | |||
− | |||
− | |||
− | |||
====z_track_parms==== | ====z_track_parms==== | ||
Line 99: | Line 107: | ||
3 col, 1 rows. | 3 col, 1 rows. | ||
ASCALE not used, but TSCALE is | ASCALE not used, but TSCALE is | ||
− | |||
− | |||
− | |||
− | |||
− | |||
− |
Revision as of 14:59, 19 January 2018
Contents
Timing Calibration Order
- 2 numbers (ADC, TDC) for each system (BCAL, FCAL etc.) Obtained by lining up the timing peak for all hits at zero. (plugin hl_detector_timing)
- Per channel: 1 number to move the TDC distributions mean to coincide with the ADC distribution mean. Average these offsets and apply to base time for TDC.
- Timewalk
- Make correlated offset to each end of the BCAL to set Z=0 at the center. Add time to one and and subtract same time to other end.
- Make correlated offset to each end of the BCAL to set global time correct. Add same time to both ends.
Concrete Steps in Calibration
macros are located at /group/halld/Users/dalton/BCAL/monitoring/macros/
- Remove 4ns ADC hardware offset (pass 1)
- Run reconstruction with BCAL_TDC_Timing plugin to produce the BCAL_TDC_Offsets/Deltat_raw/ histogram
- Run analysis script over output
- script for single run is macros/extract_ADC_Dt_Zcorr.C
- macros/monitor.py --adc4ns can be used to run over all runs
- Load constants to CCDB table /BCAL/ADC_timing_offsets using python macros/commit_CCDB.py -d output/ADCendDt/correction/ --adc
- Remove 32ns TDC hardware offset (pass 1)
- Set CCDB table /BCAL/TDC_offsets to 0
- Run reconstruction with BCAL_online plugin to produce the /bcal/bcal_Uhit_tdiff_raw_ave histogram (pass 1)
- Run analysis script over output
- script for single run is macros/extract_Uhit_tdiff.C
- macros/monitor.py can be used to run over all runs
- Load constants to CCDB table /BCAL/TDC_offsets using python macros/commit_CCDB.py -d output/tdiff/TDCcorrection/runs/ --tdc -v
- TDC timewalk correction (pass 2)
- Prerequisites:
- Remove 4ns ADC hardware offset
- Remove 32ns ADC hardware offset
- Run reconstruction with BCAL_TDC_Timing plugin
- Run analysis script over output
- script for single run is macros/fit_TDCtimewalk.C
- macros/monitor.py --timewalk can be used to run over all runs
- Load constants to CCDB
- Prerequisites:
- Position from end time-difference (pass 2)
- Prerequisites:
- Remove 4ns ADC hardware offset
- Run reconstruction with BCAL_TDC_Timing plugin
- Run analysis script over output
- script for single run is macros/
- ./macros/monitor.py --position can be used to run over all runs
- Load constants to CCDB
- Prerequisites:
- Calibrate the point time offset from tracking (pass 2)
- Prerequisites:
- Remove 4ns ADC hardware offset
- Run reconstruction with BCAL_TDC_Timing plugin
- Run analysis script over output
- Linear fit (needs ~1M events per run)
- script for single run is macros/fit_ZvsDeltaT_p1.C
- macros/monitor.py can be used to run over all runs
- Quadratic fit (needs 5 files per run)
- Linear fit (needs ~1M events per run)
- Load constants to CCDB
- Prerequisites:
- Attenuation length and gain ratio (pass 3)
- Prerequisites:
- position calibration (pass 2)
- Run reconstruction with BCAL_attenlength_gainratio plugin
- Run analysis script over output
- Load constants to CCDB
- Prerequisites:
CCDB Tables
base_time_offset
2 column, 1 rows. This is used in DBCALHit_factory.cc , it is added to the hit time Used to centre the ADC and TDC times at 0 as initial calibration
ADC_timing_offsets
1 col, 1536 row Used in DBCALHit_factory Used to remove the 4 ns timing offset.
TDC_offsets
1 col, 1152 row Used in DBCALTDCHit_factory , it is subtracted from the hit time. This is used to remove the 32 ns offset.
channel_global_offset
1 col, 768 row Used in DBCALHit_factory and DBCALTDCHit_factory , it is subtracted from the hit time.
effective_velocities
1 col, 768 row used in DBCALCluster_factory::overlap() (cluster with hit) used in DBCALPoint_factory to calculate z and throw away points > 60 cm from BCAL used in DBCALPoint to subtract the fiber-propagation-time from the time sum
z_track_parms
3 col, 768 row Used in BCALPoint to get z position from delta_t
tdiff_u_d
1 col, 768 row This is used in DBCALHit_factory and DBCALTDCHit_factory, but we agree now that it should not be.
digi_scales
3 col, 1 rows. ASCALE not used, but TSCALE is