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xTalk

Overview#

The xTalk program is used to determine cross-talk coefficients between crystals in a Clover detector. It compares the energies in Clover multiplicity 1 spectra with those in gated multiplicity 2 spectra. This process requires high statistics, so multiple runs must be combined.

Configuration File: xTalk.conf#

CAL_FILE:             Path to the detector’s calibration file  
ShiftTrack_Dir:       Path to the gain-drift alignment folder (one file per run)  
LSTSortDir:           Path to the input files (Clover-built raw data)  
OutputDir:            Path to store output files  
Source:               Source used for analysis (60Co or 152Eu)

Notes:

  • The calibration file provides approximate energy ranges for coefficient calculation
  • ShiftTrack_Dir ensures gain matching across runs (see AnaRaw)
  • LSTSortDir must point to data processed with LSTClovBuilder
  • The Source can be 60Co or 152Eu

To display help, run:

xTalk

Step 1: Generate M1 and Gated Spectra#

xTalk -read -run ...
  • Produces XTalk_Histos.root in OutputDir (or a custom name with -of Name)
  • Contains all Clover M1 spectra and 2D cross-talk matrices
  • Required for analysis in the next step

Step 2: Calculate Cross-Talk Coefficients#

xTalk -ana -file InputPars/XTalk_Histos.root

In this example, OutputDir is ./InputPars.

  • Computes the coefficient x in:
    ΔE1 = x * E2
    where ΔE1 is the energy shift in Det1 when E2 is detected in Det2
  • Produces:
  • xTalk.txt: contains all coefficients (for EventBuilder input)
  • XTalk_Graphs.root: diagnostic plots for all detector combinations

Example output for a FIPPS Clover with a 152Eu source:

xTalk ΔE Fit

Optional Step 3: Mix Sources#

To combine results from multiple sources:

xTalk -mix -file InputPars/XTalk_Graphs_152Eu_Run183.root -file InputPars/XTalk_Graphs_60Co.root

Produces:

  • Mixed_xTalk.txt: final coefficient file
  • Mixed_XTalk_Graphs.root: combined graphs

Optional Step 4: Plot Coefficients#

xTalk -plot -file InputPars/xTalk.txt

Generates a visual summary of all calculated coefficients:

xTalk Coefficients