Summary of results, signal to noise ratio for muons in HO
we (pawel and arjan) have looked at the muon signal in HO and S/N ratio.
we have looked at three runs:
9089 (ring0, eta= 3)
9123 (ring2, eta=14)
9138 (ring1, eta= 9).
these are the same runs shashi used for his analysis.
we have estimated average noise value (pedestals) and RMS of noise for
each data point using inspill pedestal events. we have used 2, 3 and 5
time slices sums.
when looking at signals, we were subtracting the average pedestal value
defined using inspill pedestals from given run. we were NOT using first 4
time slices to define pedestals on event-by-events basis, as this
technique adds to the noise.
Plots showing individual distributions:
r9089, pedestal, 5 t.s., Ring 0 and
r9089, signal, 5 t.s., Ring 0
r9123, pedestal, 5 t.s., Ring 2 and
r9123, signal, 5 t.s., Ring 2
r9138, pedestal, 5 t.s., Ring 1 and
r9138, signal, 5 t.s., Ring 1
r9138, pedestal, 3 t.s., Ring 1 and
r9138, signal, 3 t.s., Ring 1
r9138, pedestal, 2 t.s., Ring 1 and
r9138, signal, 2 t.s., Ring 1
Click here to see the table summarizing
the results.
Click here to see the table summarizing
HO RM and HPD ID numbers.
note: at 8kV, arjan claims, the HPD gain is 1800, so 1fC= 3.5 pe
these results (# of pe per ring0, ring1 and ring2 megatiles) are
consistent with what HO group measured in cosmic rays (shashi, please
confirm).
they also look consistent in terms of ability to see the signal vs size of
the noise
(3.5pe, or 1fC for 5 time-slice sums).
Click here to see the plot showing dependence
dependence
of the moun signal
on HV of HPD.
this plot was done for eta=8,phi=3 (runs 9157-9162).
Using peak (gaussian fit) values, we see a change from 1.61 at 8kV to
2.44 at 10kV (50% increase).
Using mean (average) values, we see a change from 2.33 at 8kV to 3.1 at
10kV (33% increase).
Click here to see the plot showing
Minnesota gain*QE vs HV
numbers for this particular HPD (id=55).
we see a change from 214 at 8kV to 302 at 10kV (41% increase).
Plots showing efficiency of keeping signal and inefficiency (fraction of
noise passing cuts), as a function of threshold (in fC):
r9089, 5 t.s., Ring 0
r9123, 5 t.s., Ring 2
r9138, 2 t.s., Ring 1
r9138, 3 t.s., Ring 1
r9138, 5 t.s., Ring 1
Plot done for 4time slices for Ring0
r9089, 4 t.s., Ring 0