Unpack NeuLAND Data

The working directory for NeuLAND analysis of s438b data is:

R3BRoot/macros/r3b/unpack/s438b/


The macro for standalone NeuLAND unpacking / calibration of beam data stored in LMD file is:

run_s438b_lmd_beam.C


It performs unpacking of data, channel mapping and calculation of parameters for TCAL calibration of each channel.


Execute macro

Before running the macro, make sure that paths to input / output files are properly set to the values, which are specific to your computer. The variables are: inDir, outDir, histDir. In addition, take care that the wildcard, describing your LMD file list is properly set in source->AddPath(). In case you want to add selected LMD files by hand, use source->AddFile() instead.

  1. cd R3BROOT_BUILD_DIR
  2. . ./config.sh
  3. cd R3BROOT_SOURCE_DIR
  4. cd macros/r3b/unpack/s438b
  5. root -l
  6. [..] .L run_s438b_lmd_beam.C
  7. [..] run("run336")
  8. [..] .q


Additional variables

  • nev - Number of events to be processed. -1: all events available.
  • trigger - process events only with this trigger value (1 - on-spill, 2 - off-spill). -1: all events.
  • landMappingName - Name of channel mapping name. Fragment of cfg_sig_beam.hh from land02.
  • nBarsPerPlane - Number of scintillator modules in one plane.
  • minStats - Minimal required number of entries per channel for TCAL calibration.
  • nModules - Total number of Photo-Multipliers (nBars*2).
  • type, subType, procId, subCrate, control - MBS parameters of NeuLAND sub-event.

View TCAL parameters

Time Calibration parameters are calculated after event-loop and are stored in the parameter file "params_runRUN-NUMBER_raw_land.root". They can be displayed for each photomultiplier separately using the macro

view_tcal_par.C

Path to location of unpacked data has to be adjusted (variable inDir). Parameters of the function are: run number (string), bar index (global counting), side (1 or 2).

  1. root -l
  2. [..] .L view_tcal_par.C
  3. [..] view_module("runRUN-NUMBER", BarNo, Side)
  4. [..] .q

This will display histogram with TAC channels on X axis and time in [ns] on Y axis.
Next How-To describes how to apply obtained parameters to produce time calibrated NeuLAND data.