[Tpe] TPE Calorimeter

[Larry Weinstein]

Dear Folks,

We added an amplifier to the TPECal circuit today.  That now replaces 
the first splitter (since it has two outputs).  We then adjusted the 
amplifier gain with the HV off so that the noise on any one channel is 
less than 28 mV (after the splitter).  We then adjusted the HV of each 
channel so that we saw 1-3 100 mV signals in 10 seconds.  (Finer gain 
matching will be done with the ADC spectra later).  HV are recorded in 
the paper TPECal log book.  I also raised the discriminator threshold on 
the ADCSum (that provides the trigger) to 100 mV (1 V on the DVM).

TPECal things to do:
  1) check with scope that each channel gives discriminator pulses
  2) increase the TDC discriminator thresholds to 50 mV
  3) take data and
     a) check ADC spectra
     b) check TDC spectra
  4) increase TDC disc thresholds until you see a nice peak in the TDC 
spectrum.  Look at the 2D ADC vs TDC spectrum to see what ADC channel 
corresponds to that threshold
  5) analyze the data to see the maximum minimum ionizing signal (using 
Rob's no-neighbor algorithm)
  6) gain match the ADCs

-- 
				Sincerely,
				Larry

-----------------------------------------------------------
Lawrence Weinstein
University Professor
Physics Department
Old Dominion University
Norfolk, VA 23529
757 683 5803
757 683 5809 (fax)
weinstein at odu.edu
http://www.physics.odu.edu/~weinstei