Last Wednesday, Nico Mazziotta enlarged the time coincidence window for
accepting events from separate microvaxes into the same event number.
This gate for inter-microvax events is now 200 microseconds.
During the Rome meeting, the possibility of bringing this gate up to
1ms was examined. This would allow very slow particles crossing different
microvaxes (in all geometries) to result in a single event rather than two
separate events, one for each microvax. This was abandoned though as it
requires substantial work at the hardware level to make sure it does not result
to MACRO RUN crashes and also work at the analysis level to make sure that
no other analyses are affected.
The first run following this change was 13398 which started on Wednesday,
January 22, 1997 at 20.588 Although the 200 microsecond inter-uVax window can
not cover all geometries down to beta=10^-4, it approaches close to that for
pathlenghts ~9m at it thus presents a major improvement. Repeating a cross-uvax
calibration run is in our schedule. Notice that this inter-uVax timing window
is affecting scintillator triggers *only*. Streamer tube triggering on this
type of events, is already taken care of at the trigger formation level.
For those of you not logging on VAXGS frequently, Nico's original posting
follows.
Let me know if you observe any problem in the data. We nominally expect the
total number of events in a run to slightly decrease. Also, the TOHM face
coincidences that involve SMs in different microvaxes should increase.
--Erik Katsavounidis
News 651 in MACRO.GENERAL on node AXPGS2 VaxNews 3.21
Newsgroups: MACRO.GENERAL
From: AXPGS0::MAZZIOTTA
Subject: New Microvax coincidence window (corrige)
Date: 22-JAN-1997 13:23:07.38
Expires: 21-FEB-1997 13:23:07.38
Path: axpgs0.lngs.infn.it!vaxnews!MAZZIOTTA
Message-ID: <00003814_VAXNEWS@axpgs0.lngs.infn.it>
As discussed in Rome (Jan. 17th 1997) during the meeting on the MACRO
hardware status, today 22/Jan/97 the MicroVax coincidence window is being
displaced from 8.8 microsec (supposed to be 10 micosec!) up to 200 microsec.
This allow for lower monopole Beta value for the scint. FMT.
N. Mazziotta, E Katsavounidis, A. Sciubba, G. De cataldo