Reported by: Hwi Kim
Present: Lory Gray, Erik Katsavounidis, Ioannis Katsavounidis, Hwi Kim,
Sophia Kyriazopoulou, Chris Orth, Massimo Orsini,
Valeriano Marrelli, Nicola Zaccheo
0. News from Gran Sasso
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The whether has been hot and humid, mostly clear but with a mild thunderstorm.
The mountain is not as breathtakingly beautiful as October 1997 when I first
visited Gran Sasso. But, it sure is beautiful!
Ioannis came back from California after successfully defending his Ph.D.
thesis.
Now, you have to sign (in the guard house) for your bottle of water in the
tunnel. I hear that the ratio of the number of visitors to the number of
bottles taken per day is 1:1 now. Before, it was 1:10.
1. Data taking
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Data taken during 11 July - 6:00 pm 24 July 1997: Runs 16090 - 16160
The following are the problems that occured during the shift.
- The phototube of 4B06-0 is found to be noisy and it is turned off during
runs 16100-16117. The phototubes and cards are replaced.
- Run 16121 crashed and the subsequent effort to start the run failed due
to syncronization problem in mVax 2. This is fixed by cycling the power
on the syncronization units.
- Power trip of SM5 PHRASE crate caused the run 16128 to crash. All available
power supplies are tried but none worked. The next day, the problem is
found to be the fan unit and it is replaced.
- TRD crate went off during run 16133 (system error in mVax 3)
- The active termination on the data bus of the WFD readout VME crate on SM6
failed during runs 16133 - 16139. The termination is switched to passive
and run 16144 is started.
- Data from mVax 3 is corrupted during the runs 16140-16144 due to a damaged
pin of a CAMAC cable.
- H.V. Cards are replaced on 3B08-1.
- Streamer tube wire read out card on module 10 went bad. Affected runs are
16152-16155.
- cSPAM low efficiency problem in SM6 is fixed.
- The gass system went off eighteen times starting from the 10th till the
morning of the 13th. The cause was same all the time: "pressure in tank C
out of range." The N-Pentano recover(y) is excluded to avoid gas system
crahses.
- DGN & VSMAC2 crashes. DGN will be serviced in the week of 27th July.
2. Calibration and Maintenance
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The following calibrations are done.
Laser calibration: mVax 1 (Runs 91081, 91082), vVax 2 ( Runs 91092, 91094)
LED/TDC: mVax 2 (Run 91088)
Monopole: mVax 1 (Run 91084)
Lamosska: mVax 1 (Run 91083), 2 (Run 91097)
3. Rare DST production
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There is a big effort going on to produce Rare DST in ZEBRA format for
the American collaborators. Erik, Ioannis, Chris Orth and three technicians
are involved in the effort and have already produced seven copies of
the DLTS for each American institutions. It is expected that we will
produce about one DLT per day. Chris Orth will bring back the copies
for Boston, Caltech and Texas and I will bring back whatever is produced
by next Friday. Hopefully, all 22 DLTS will be produced by the time
Bob Webb leaves Gran Sasso. After that, the recent runs will be copied
to DLTS.