We connected an MCM to the test setup in 218, and collected 1500 data packets.
The data were collected in 252-event chunks, and appended to the same (ascii)
file. (after ~252 triggers, something went wrong in the readout - I ignored
that for the moment). The MCM was not connected to anything, and also not
shielded in any way. These events were collected over the span of ~5 hours.
ps
- The first panel shows that the AMU cell number is evenly distributed.
- The second panel shows the raw ADC values vs channel number. The 6th
group of 32 channels is dead.
- The third panel shows channel 193 vs data packet number, that is, it is a
time history of this one channel. Something went wrong
around event 800-1000, I'm guessing this is a block of 250 event I took
immediately after a power-up, and the electronics had not yet settled and
warmed up. Note that there is no overall drift between the
beginning and ~5 hours later.
- Panel 4 shows, on a log scale, the raw ADC values for channel
193. The outlyers are caused by triggers that unfortunately coincide with the
periodic resets of the preamp/integrator.
- Panel 5 shows the main peak, and I defined a 'good data' cut between 380
and 410, and used it for all channels.
- Panel 6 shows what passes. The fit shows a pedestal sigma of 1.60
channels
ps, page 2
The 8 panels above show ADC vs AMU channel, for each of the 8 groups of 32
channels. A faint 4-cell periodicity may be discerned, but nothing dramatic
like
in the real data
ps, page 3
I did a fit to the data of group 7. The fit is of the form
P1 + P2*sin(P3 + P4*x)
It shows that the amplitude is 0.82 ADC channels
next test: MCM + cable and detector
Last update 2 Nov 2001 - HvH
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