(1) I filtered on muon events with max ADC counts greater than 200. Several
events show the positive overshoot following the big amplitude pulse
causing the discriminator to fire for several usec following the pulse.
I see this on channels on all supermodules and it does not seem to
be restricted to a few misbehaving inputs. However, not all events
from a given input (with max adc counts > 200) show this behavior.
Further, there seems to be no correlation with the pulse height.
e.g Run 10387 Channel ID 605
Event 3462 with maxADC counts =~ 205 shows this behavior
but Event 3450 with maxADC counts =~ 225 does not.
For both events the big pulse is on input 1.
The events which show the positive overshoot have a distinct afterpulse
of a few 100 mV about 2 usec following the big pulse. The afterpulse is
not always distinct on events that do not have the overshoot.
The overshoot always seems to last for about 25-30 usec following the
big pulse.
(2) I looked at a few events with max ADC counts between 170-180. None
of these showed the overshoot. I haven't yet mapped the ADC range to see
where this behavior makes its appearance.
(3) Channel ID 60B has its ADC counts stuck at around 256 following a big
pulse. The inputs look noisy, too.
- Ash