| E08-010 ~ N-Delta Database Files |
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Calibrations of the various detectors used in the experiment produce values that are stored in files in a database directory. The analyzer
accesses these files to determine how the various detector modules are configured. Usually, the database directory, often referred to simply as the "DB" directory, contains three files in the root directory, with the rest of the detector-specific files stored in numbered subdirectories whose names correspond to the dates when those files become relevant. For example, if the files in a particular directory become valid on October 31st, 2008, that directory name should be "20081031". Over the course of the N-Delta experiment, there were no changes requiring a change in the database files, so any date prior to the beginning of the experiment (February 26th, 2011) should work, such as "20000101" (January 1st, 2000). |
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| Main Files | |
| db_cratemap.dat |
The db_cratemap file contains data pertaining to the location and type of cards in the various crates. Respectively, crates 1 and 2 correspond
to ROCs 1 and 2 in the RHRS, while crates 3 and 4 correspond to ROCs 3 and 4 in the LHRS. 1881 is the model type for the ADCs, while 1877 and 1875 are the model types for the TDCs. The 1877 has a 0.5 ns resolution, while the 1875 has a 0.1 ns resolution. For the N-Delta experiment, only 1877s were used. Also, the 1877s use common stop rather than common start, so the information from these TDCs are backwards in time, and the signals with the highest channels actually arrived first in time. |
| db_run.dat |
The db_run file contains data pertaining to the different spectrometer configurations used throughout the experiment. Each entry begins with a timestamp; all runs that took place AFTER this timestamp will use these settings. Following the timestamp is a comment indicating which Kinematic the entry refers to and which runs should be included, matching what is shown on the Experiment Timeline page. Additional information, including beam energy, spectrometer angle and momenta, and mispointing offsets follow. Also, it should be noted that all timestamps are designed for Halifax analysis (Atlantic time), and are set to be 1 hour ahead of the actual times (Eastern time) from the experiment. |
| scaler.map |
The scaler.map file maps the names of the scalers with the location in the crates where the scaler data was recorded. During the experiment,
this was relevant because these names were used in the interface used to keep track of the scaler rates. In the analysis phase, these names refer
to the variables in the scaler trees of the ROOT files. In the file, each scaler is listed with its location by crate, slot, and channel, as well as with a longer description. (For reasons I can't explain, problems occur when trying to download this file as "scaler.map", so the file is actually named "scaler.dat". Just rename it upon download.) |
| Subdirectory Files | |
| Many of these files refer to a specific detector in one of the two spectrometer arms. The general format for these files includes the specific ADC and/or TDC channels where the information comes in, the physical location of the detector, and various tables of constants obtained from the detector calibrations, such as pedestal values and other offsets. | |
| db_beam.dat |
This file holds the calibration values for the various beam detectors, including BPMA, BPMB, and the Raster. Technically, the analyzer actually looks for three separate files (db_rb.Raster.dat, db_urb.BPMA.dat, and db_urb.BPMB.dat) for each of those devices, but by creating those three files as hard links to db_beam.dat, this one file can handle all three devices, and one need only adjust this one file to make adjustments to all three devices. The data for this file was determined from the BPM Calibration. As mentioned on that page, the raster constants in this file are an average of the raster constants obtained from all 12 of the kinematics. |
| db_DBB.dat |
This file holds data pertaining to the analyzer's decoder class. This class is useful for collecting data on an event by event basis
for things like the EDTM and the triggers. The format of this file includes the name of the variable (to follow the "DBB." prefix in the T Tree of the ROOT file) and the where the data is recorded in the crates. This formatting allows any channel in any crate to be looked at independently from the rest of the analysis, even the data already being recorded for other purposes, which is incredibly helpful in finding problems with the analysis. |
| db_L.cer.dat |
This file holds calibration data for the Cerenkov detector in the left arm. Since that detector wasn't used in this experiment, this file isn't necessary unless the Cerenkov detector has been added to the list of detectors in the replay file. |
| db_L.prl1.dat |
This file holds calibration data for the first layer of the pion rejector in the left arm. There are no TDC calibrations in this file because the pion rejectors do not record TDC information, only ADC. Additionally, there are values in this file to help convert from ADC values to energy. |
| db_L.prl2.dat | This file holds calibration data for the second layer of the pion rejector in the left arm. |
| db_L.s0.dat |
This file holds calibration data for the S0 layer in the left arm. This layer is primarily used for efficiency checks of the other two scintillator layers, S1 and S2. Due to the presence of the FPP in the left arm, the usual S0 layer was removed and a temporary S0 layer was installed. For this reason, the values in this file may be incorrect. |
| db_L.s1.dat |
This file holds calibration data for the S1 layer in the left arm. For this experiment, the calibration of the scintillators primarily consists of adjusting the time offsets to align the TDCs. Due to a wiring problem, the TDCs of this layer are effectively self-timed. |
| db_L.s2.dat |
This file holds calibration data for the S2 layer in the left arm. Like the S1, the calibration of these scintillators primarily consists of adjusting the time offsets. Due to the miswiring mentioned in the previous entry, the TDCs in this layer have double-peak issues. |
| db_L.vdc.dat |
This file holds the calibration data for the VDCs in the left arm. The time offsets values in this come from the VDC Calibration. |
| db_R.cer.dat | Unlike the Cerenkov detector in the left arm, the Cerenkov in the right arm was used during the experiment, and could be important in particle identification. |
| db_R.ps.dat | This file holds information on the preshower counters in the right arm. This and the shower counter are roughly analogous to the pion rejectors in the left arm. |
| db_R.s0.dat | Like the left arm, this layer is primarily used for efficiency checks of the two primary scintillator layers. |
| db_R.s1.dat | Normally the wires on one side of the S1 scintillator bars are longer than those on the other, so that one side always arrives as the logic modules last, thus setting the timing. For some reason, the wires on this layer were the same length, so the timing switches back and forth between sides, causing timing issues. |
| db_R.s2.dat | Due to problems with the pedestal suppression in this arm, there are no ADC values for the S2 layer. |
| db_R.sh.dat | This file holds calibration information for the shower counters in the right arm. Paired with the preshower counters, they are analogous to the pion rejectors in the left arm. |
| db_R.vdc.dat | Like the left arm, this file contains calibration data for the VDCs, the values for which come from the VDC Calibration. |