01) raw spectra

 Goals:

  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

 Method:

  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.

 

Conclusions:

  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?