01) raw spectra


  1. verify pedestals loaded to DB are reasonable for 2008 pp data
  2. estimate stats needed to find slopes of individual strips for minB events


  1. look at pedestal residua for individual strips, exclude caps 1 & 2, use only status==1
  2. fit gauss & compare with histo mean
  3. find integrals of individual strips, sum  over 20 ADC channels starting from ped+5*sig 

To obtain muDst w/o zero suppression I run privately the following production chain:

chain="DbV20080703 B2008a ITTF IAna ppOpt VFPPV l3onl emcDY2 fpd ftpc trgd ZDCvtx NosvtIT NossdIT analysis Corr4 OSpaceZ2 OGridLeak3D beamLine BEmcDebug"

Fig 1

Examples of single strip pedestal residua, based on ~80K minB events from days 47-65, 30 runs. (1223 is # of bins, ignore it).

Left is typical good spectrum, see Fig2.3. Middle is also reasonable, but peds is 8 channels wide vs. typical 4 channels.

The strip shown on the right plot is probably broken. 

Fig 2

Detailed view on first 500 strips. X=stripID for all plots.

  1. Y=mean of the gauss fit to pedestal residuum, in ADC channels, error=sigma of the gauss.
  2. Y=integral of over 20 ADC channels starting from ped+5*sig. 
  3. Raw spectra, Y=ADC-ped, exclude caps 1 & 2, use only status==1


Fig 3

Broader view of ... problems in BSMD-E plane. Note, status flag was taken in to account.

Top plot is sum of 30 runs from days 47-65, 80K events. Bottom plot is just 1 run, 3K events. You can't distinguish individual channels, but scatter plot works like a sum of channels, so it is clear the slopes are there, we need just more data.



  1. DB peds for BSMDE look good on average.
  2. with 1M eve we will start to see  gains for individual strip relativewith ~20% error. Production will finish tomorrow.
  3. there are portions of SMDE masked out (empty area in fig 3.2, id=1000) - do why know what broke? Will it be fixed in 2009 run
  4. there are portions of SMDE not masked but dead (solid line in fig 3.2, id=1400) - worth to go after those
  5. there are portions of SMDE not masked with unstable (or wrong) pedestal, (fig 3.1 id=15000)
  6. for most channels there is one or more caps with different ped not accounted for in DB ( thin line below pedestal in fig 2.3)
  7. One gets a taste of gain variation from fig 2.2
  8. Question: what width of pedestal is tolerable. Fig 2.1 shows width as error bars. Should I kill channel ID=152?