Generating Field Response Data File.
(top) (pkg)

Get the output of Garfield 2D which should be a collection of files like:

<impact>_<letter>.dat

Where

<impact>

gives the impact position in mm (eg 0.9)

<letter>

indicates the plane (eg, U, V or Y)

Contents of the file should be like:

*----.----1----.----2----.----3----.----4----.----5----.----6----.----7----.----8----.----9----.---10----.---11----.---12----.---13--
% Created 31/07/16 At 19.52.20 < none > SIGNAL   "Direct signal, group   1     "

  Group 1 consists of:
     Wire 243 with label X at (x,y)=(-3,0.6) and at -110 V
 Number of signal records:  1000
 Units used: time in micro second, current in micro Ampere.
 .STIMULUS signal PWL
 + TIME_SCALE_FACTOR =  0.100E-05
 + VALUE_SCALE_FACTOR =  0.100E-05
 + (  0.00000000E+00   0.00000000E+00
 +     0.10000000E+00   0.00000000E+00
 +     0.20000000E+00   0.00000000E+00
...
 +     0.99599998E+02   0.00000000E+00
 +     0.99700005E+02   0.00000000E+00
 +     0.99800003E+02   0.00000000E+00
 +     0.99900002E+02   0.00000000E+00 )
% Created 31/07/16 At 19.52.20 < none > SIGNAL   "Cross-talk, group   1        "

  Group 1 consists of:
     Wire 243 with label X at (x,y)=(-3,0.6) and at -110 V
 Number of signal records:  1000
 Units used: time in micro second, current in micro Ampere.
 .STIMULUS signal PWL
 + TIME_SCALE_FACTOR =  0.100E-05
 + VALUE_SCALE_FACTOR =  0.100E-05
 + (  0.00000000E+00  -0.15888787E-10
 +     0.10000000E+00  -0.31810016E-10
 +     0.20000000E+00  -0.31853374E-10
 +     0.99800003E+02  -0.58125088E-16
 +     0.99900002E+02  -0.58125088E-16 )
...
  Group 21 consists of:
     Wire 263 with label X at (x,y)=(3,0.6) and at -110 V
 Number of signal records:  1000
 Units used: time in micro second, current in micro Ampere.
 .STIMULUS signal PWL
 + TIME_SCALE_FACTOR =  0.100E-05
 + VALUE_SCALE_FACTOR =  0.100E-05
 + (  0.00000000E+00  -0.15898597E-10
 +     0.10000000E+00  -0.31829737E-10
 +     0.20000000E+00  -0.31873192E-10
...
 +     0.99700005E+02  -0.58160981E-16
 +     0.99800003E+02  -0.58160981E-16
 +     0.99900002E+02  -0.58160981E-16 )

Wire Cell Toolkit works with JSON data. Python code in wire-cell-python package is provided to convert Garfield 2D files into properly structure JSON.

$ cd wire-cell-python/
$ virtualenv --system-site-packages venv
$ source venv/bin/activate
$ python setup.py develop
$ wirecell-sigproc convert-garfield --help
Usage: wirecell-sigproc convert-garfield [OPTIONS] GARFIELD_FILESET
                                         WIRECELL_FIELD_RESPONSE_FILE

  Convert an archive of a Garfield fileset (zip, tar, tgz) into a Wire Cell
  field response file (.json with optional .gz or .bz2 compression).

Options:
  -o, --origin TEXT          Set drift origin (give units, eg '10*cm').
  -s, --speed TEXT           Set nominal drift speed (give untis, eg
                             '1.114*mm/us').
  -n, --normalization FLOAT  Set normalization: 0:none, <0:electrons,
                             >0:multiplicative scale.  def=0
  --help                     Show this message and exit.
$ wirecell-sigproc convert-garfield ub_10.tar.gz ub-10.json.bz2 
$ wirecell-sigproc plot-garfield-track-response ub_10.tar.gz tr.pdf

Notes:

• Using --system-site-packages may be useful as Numpy is required and if it’s installed as a system package it will save you some time. O.w., it can be installed into the virtualenv.
• Once you generate the .json.bz2 file, you no longer require this code so deactivate and clean up
• The plotting command is optional. It remakes a plot for the MB noise paper and is reproduced below
• Warning the plot below is not final nor official.

./tr.pdf