User name Peter L
Log entry time 17:36:22 on July18,2004
Entry number 128880
This entry is a followup to: 128774
keyword=Results of scanner linearityHere are a number of plots which illustrate the scanner PMT
linearity. These are of run 2917 where the detector was placed on
the elastic peak and MCC ramped the current.
The top two plots are profiles of the left and right detector vs bcm3
and lines fitted to them. The lower two are the differences of fit
to signal(residuals). One notices right away that the right PMT has
a much greater gain than the left(even though it is at a lower voltage).
The difference in the rightcorresponds to gain as follows:
Right:
Pedestal to peak(at 38uA) is 35000 channels. The greatest
difference in fit to signal is ~300ch, which is ~0.8% signal
integral nonlinearity.
Left:
Pedestal to peak(at 38uA) is 15000ch. The greatest difference in fit
to signal is ~300ch, which is 2% signal integral nonlinearity.
FIGURE 1
