Present at LNGS: Fabrizio Cei, Erik Katsavounidis, Ioannis
Katsavounidis, Sophia Kyriazopoulou, Roberto Giuliani, Massimo
Orsini, Kate Scholberg (minus week of Feb 22), Nicola Zaccheo
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Things that happened:
=====================
-- On Sun, Feb 21, two PHRASE power supplies failed. They were
replaced on Monday.
-- On Wed Feb 24, the power to the entire detector was shut down in
order to replace some automatic switches (these are supposed to
automatically switch off power for the case of a smoke alarm;
installation was planned for several months ago but they were found to
be wrong switches). No calibrations were done on this day. The power
shutdown caused several problems:
* a TOHM attico power supply failed.
* after this shutdown, microvax 2
went into a mysterious failure mode: it came up, but refused to talk
to any of the other microvaxes. Eventually the run was started
without this microvax, and left out overnight. The next day, it just
as mysteriously started working again.
* some fan failures for PHRASE SM 1 top caused crate overheating
and PHRASE failures. The fans have been replaced.
-- Starting Friday Feb 26, a network problem in the tunnel caused
various troubles: it was no longer possible to log on to VXMACA from
outside, and in addition the secondary links to the microvaxes did not
work. The run still continued, however. A DEC technician was called
but did not arrive until Wednesday Mar 2. The problem -- a broken
routing device -- was not fixed until Wednesday evening. For this
reason, there were no calibrations on that Wednesday either.
-- On Monday March 2, tank 3W02 started giving a high rate. It was
turned off by the techs, but not turned back on until Wednesday
(due to the network problems). They found that the tube was overgain
by 200 V, for unknown reasons. They're trying to track down the
records for this tube.
-- On Wed March 4, the same failure mode as mentioned above recurred
on microvax 2. Again, it mysteriously came back to life
when Attanasio Candela arrived on Thursday morning and waved his hands.
-- On Thursday March 5, Ioannis and I did a new kind of GC LED test (a
day later than the original plan, due to the aforementioned network
problems). The test run was run 91329 on microvax 2. We simulated
three bursts, with each burst taking about one and a half minutes
(including time for fake box flags and delays), and with intervals of
a few minutes in between each burst. Unlike for previous tests, the
boxes were fired *one at a time*, and *synchronized* with the pulsers,
i.e. the LEDs were fired once for every switchbox change. The boxes
fired were written to a log file, which should allow GC efficiency
checks. Rates of 35-40 Hz were achieved, thanks to a new fast pulsing
Camac routine written by Ioannis. The fired boxes were randomly
generated (weighted by mass), but with the same random seed for each
execution of the program, so it was the same box sequence for each
burst (except for possible small differences due to slightly different
delays for some iterations). See the macro-erpgc mailing list
archives for more details about this run. Everything went very
smoothly; analysis of the run is in progress.
-- As of Thursday afternoon, DGN stopped working, for unknown reasons.
On-going goings-on (hey, a word palindrome!):
==============================================
-- Erik has devised new log files which keep track of data size and
other rates by trigger for each run, to help track down such problems
as high dead time, high trigger rate etc. He also has made some nice
new web pages with quick online information about recent monopole
candidates.
-- Erik has also pointed out an intermittent problem we've actually had
for some years now, with the top face SM 6 TOHM: sometimes you
get waveforms (and apparent triggers according to the SPU), but with
no TOHM trigger information. This happens about once every 30 runs.
-- Massimo has been investigating some possible pmt gain problems,
identified by Ioannis as having mismatched tankend gains according to
the ERP muon calibrations. There are 12 Ham verticals, 9 N/S, 7 EMI
verticals and 3 horizontals with this problem. Interestingly, the
PHRASE calibrations turn up roughly the same list of mismatched tubes.
-- Ioannis and Nicola continue work on ERP calibrations; please
see recent postings to the macro-cal mailing list.
Reportaggio Personale:
======================
This Thursday, a MACRON of yore, Rich Baker, arrived at LNGS with his
wife, Kathryn, en route to a conference in Frascati. He's now doing
well as a postdoc at CLEO (where they have "rate") and continues to
work his way up in the world of Scrabble. I missed his talk on
Friday, but made it to dinner at the Fish Place, where we partook of
trout and reminisced about old times.