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Jens Janssen edited this page May 27, 2015 · 16 revisions

Application notes

Special features and applications using pyBAR are listed here. Corresponding code is e.g in the example folder or the links are mentioned.

Charge reconstruction: Threshold-Method

Content:

  • Charge reconstruction method to get single pixel charge spectra
  • Shift the threshold while measuring the particle rate to record the integrated charge spectrum
  • Noise < 200 e
  • Statistical method, no single hit charge
  • Published method

Use calibrate_threshold.py to create a threshold calibration per pixel. Then put a source on the FE or go to a test beam and run scan_ext_trigger_gdac.py. For the analysis of the data use analyze_source_scan_gdac_data.py.
 

 

Charge reconstruction: TDC-Method

Content:

  • Charge reconstruction method to get single pixel charge spectra
  • Use the FPGA TDC to digitize the TOT-Signal with a 640 MHz clock
  • Noise 300 – 1000 e, depending on the tuning
  • Single pixel hit charge can be measured

Use 2 open drain buffers to amplify the Hit-Bus signal and modify the MIO to translate the H/Z signal to H/L:
 

 
Use calibrate_hit_or.py to create a TDC calibration per pixel. Then put a source on the FE or go to a test beam and run scan_ext_trigger.py with enable_tdc: True. For the analysis of the data use analyze_source_scan_tdc_data.py.
 

 

Primlist: Measure Signal-to-Noise for the TOT-Signal using the TDC-Method

Content:

  • Shows how to use write a prim list
  • Chip parameters are changed within a loop
  • Results are analyzed and plotted within the same script

A prim list prim_list_tdc_sn.py is used to change the parameters that change the signal-to-noise of the TOT-Signal: discriminator bias, feedback current and threshold (DisVbn, PrmpVbpf, Vthin_AF). One can see that low threshold / low feedback / high discriminator bias tunings give a better S/N.