Sophia, Massimo, Valeriano, Nicola, Erik, Chris Orth, Lori, and me (Nat).
Generally good running with intermittent downtime related to minor
ERP, PHRASE, and DGN problems:
Mon 1 Jun 3C08-10 base failure requiring restart. Needs new LUTs.
Sat 6 Jun Loss of 5T05-5T08. New LUT's no help - bad sample & hold.
Mon 8 Jun Reinstalled 3C08-10.
Tue 9 Jun Reboot VSMAC2 for DGN crashes. Reboot Pisa MV6 for LSCM.
Wednesday 3 June: uVAX 2 calibration.
All six LeCroy HV cooling fans were replaced in SM2, in which all but
one had failed. A subsequent survey indicated that a total of six
additional fans had failed on the other five SMs. New fans were
ordered and a plan to inspect the fans and clean filters on
a monthly basis was implemented.
Wednesday 10 June: uVAX 3 calibration.
The 5T05-5T08 Sample and Hold was replaced. Some indications were
discovered of "flakiness" in the SM6 LAMOSSKA delay generator.
Operational now. but planning to inspect solder joints and circuitry
to find source of previous problem.
Thursday 11 June: an additional CAMAC crate was added to the spare
uVAX branch. This will be used to communicate with the Pulser and LED
switchboxes in an attempt to reduce deadtime (and hence total elapsed
time) during calibration runs. Although the total branch is
approxmately 40 m long (the spare uVAX is near SM 1 and the Pulser is
near SM 4), both crates pass borer and DSP tests.
Front panel plates were designed for the WFD/ERP/NIM monitor cards,
and will be installed by Massimo/Nicola/Valeriano.
Texas and BU were asked to supply replacement +/- 12 V and - 5 V power
supplies in order to bring the spare WFD crate back on line.
General comments:
The technicians are as usual doing an excellent job, even in the
absence of Ioannis, who is apparently finishing his PhD in California
but will return within the month. Erik also deserves credit for the
excellent way in which the crew manages the detector.
Even under the best circumstances it is difficult to interupt the run
without some probability of 10-15 minutes' deadtime before successful
restart. I made a case that we should in general defer attempts to
return scintillator boxes to ACQ until maintenance days, unless there
are more than four involved. Of course only the PIC can make
day-to-day judgements on this issue.