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DWC calibration

The delay Wire Chambers should be calibrated before the start of a test beam.

The instruction to perform the calibration are tin the attached pdf file.

Calibration signal

t (ns) V (mV)
0 0
10 Vmax
30 Vmax
90 0
Vmax = 40mV according to the manual, but you should probably use Vmax > 100mV because the discriminator thrs is set to 40mV. The pulse frequency should be f < 10kHz. Actually you can use a square pulse of width ~40ns.

Calibration with the DAQ

If you want to use the DAQ for the calibration you'll have to provide a trigger in sync with the calibration pulse. The quantities (up - down) and (right - left) can then be found in one of the online histograms (debug folder). Take one run for each of the three calibration inputs (up-left, center and down-right).

The new macro to compute the calibration is dwc_calib.cxx. Just change the number of the calibration runs at the bottom of the file.

Manual calibration

Measure the time (up - down) and (right - left) for each of the three calibration inputs (up-left, center and down-right).

The old macro to do the calculation is calibration_DWC1_Jul2012.cxx, just change the values of this variables

  • float ud_left_up
  • float ud_right_down
  • float ud_center
  • float lr_left_up
  • float lr_right_down
  • float lr_center
with what you measured.

The calibration should be updated in the monitoring software and in the ntuple production program.

-- MicheleCascella - 15-Jul-2012

Topic attachments
I Attachment History Action Size Date Who Comment
PDFpdf DWC_calibration.pdf r1 manage 368.1 K 2012-07-15 - 21:36 MicheleCascella  
Unknown file formatcxx calibration_DWC1_Jul2012.cxx r1 manage 1.9 K 2012-07-15 - 21:31 MicheleCascella  
Unknown file formatcxx dwc_calib.cxx r1 manage 2.5 K 2014-11-28 - 15:22 MicheleCascella New calibration macro
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Topic revision: r4 - 2014-11-28 - MicheleCascella
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