Analysis codes

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Calibrations for bin_dgs in GEBSort_nogeb

GEBSort_nogeb is the program that can analyze data from DGS, DFMA and GRETINA.

You can get if from here:

cd workdir (e.g., /home/gtuser/gebsort)
  svn co https://svn.anl.gov/repos/gs_analysis/GEBSort .
or
  wget http://www.phy.anl.gov/gretina/GEBSort/AAAtar.tgz
  tar -zxvf AAAtar.tgz

To produce the PZ spectra and 2D [sum2-sum1] vs [sum1] matrices needed to determine the PZ fudge factor (FF) you must enable

 #define ALL2DS 1

in bin_dgs.c and recompile . We do not always want these spectra as they take up a lot of space, but for now we need them

You now specify the PZ and ecal files in the GEBSort.chat file with these lines:

 dgs_MM      350
 dgs_PZ      dgs_pz.cal
 dgs_ecal    dgs_ehi.cal

Before you start sorting data, you need to check that the map.dat file is up to date and reflects the array as it is configured.

For DGS data, enable bin_dgs in the GEBSort.chat file. To find the PZ values to use, sort some data from a 207Bi source. Then extract the pz spectra in .spe format with the get_pz.cc script

  GEBSort_nogeb ....
  rootn.exe
  dload("bi.root")
  .x get_pz.cc

Now run:

  dgs_pz 350 141 dgs_pz.cal 1.003

where 350 100 are the M and K values you find in the runxx.save file. Specify the values in 10 nsec units. In this case I saw these lines in the .save file:

 caput GLBL:DIG:d_window 0.06   
 caput GLBL:DIG:k_window 0.20     
 caput GLBL:DIG:m_window 3.50
 caput GLBL:DIG:k0_window 0.80
 caput GLBL:DIG:d3_window 0.20
 caput GLBL:DIG:raw_data_window 0.32
 caput VME01:SDIG1:k0_window0 0.0
 caput VME01:SDIG1:k0_window1 0.0
 etc

for the K value: sum up all the K and D values, in this case: 0.06+0.20+0.80+0.20 = 1.26 us or 126 in 10 nsec units. Notice that what is considered the K value also includes the D values (per SZ 6/25/18) as well as a D2 which is fixed at 0.15 (per JTA 6/26/18) and not in the listing above because the user cannot set it. Thus, in total, K in this example is 1.41 us or 141 in 10 ns units. The M value is 3.50 us or 350 in 10 nsec units. The 1.003 is a modification factor that needs to be determined by looking at energy vs baseline spectra.

 you already specified the M value in GEBSort.chat

Now, after the PZ file is generated, remove the energy calibration file if there is one:

 rm dgs_ehi.cal

so that the calibrations defaults to 0 and 1 for offset and gain and sort again using the new pz values that were extracted above. When you resort, the PZ values in dgs_pz.cal are read in and used. Extract the new clean, uncalibrated, ehi spectra as

  .x get_ecln.cc

and run the calibration program

  dgs_ecal dgs_ehi.cal 207Bi 600

you can also use "88Y", "60Co" for the source. The calibration will be 1keV/ch. The last parameter specifies the lowest channel the program will search for peaks in to avoid noise at low energies.

Next when you run GEBSort_nogeb, both the new PZ values in dgs_pz.cal and the gain and offset values in dgs_ehi.cal are read in and used. Take a good look at the spectra. Sometimes the dgs_pz and dgs_ecal programs can be fooled by noise of starnge features in the spectra, so some PZ and ecal parameters might have to be specified by hand.

The energy processing in bin_dgs follows algorithms that were developed by Shoufei Zhu.