Scint people at Gran Sasso during this period: C. Bower, M.
Goretti, E. Katsavounidis, N. Lu, D. Michael, P. Saggese
Reporter: N. Lu
With pasta ordered hot from Fiordigigli, natural light and warmth
in the external lab, everyone looked happy at the beginning of this
MACRO meeting. Still with a smile on his face, Erik warned us of the
upcoming gasoline strike that was to last for four days. Maurizio
kindly reminded Doug that the Caltech car is almost empty. Wow,
whatever happens outside of the tunnel actually concerns us, we don't
just live in our seperate little world under Gran Sasso.
Erik has noticed that the runs from Friday, 15th, to Monday, 18th,
run number 10922 to 10934, have the led calibration flag on. They are
actually all normal runs without any interruptions between them.
Maurizio checked the SPU and found nothing wrong. I recalled that I
had done some led calibration test on the HP pulsers, but I had
disconnected all cables from the pulsers. The problem was found gone
by itself later on Monday.
Erik reported that there are four dead ERP channels in SM1, 1C13,
1C14, 1C15, and 1C16. Last maintenance day Paolo has taken the ERP
card out that has these four channels and found nothing wrong. He
tried to swap cables to this card and found nothing wrong. Doug and
Erik played with it and once they put everything back and this card
worked. But all four channels on this card were found dead again a few
days later. So it must be an intermittent problem, maybe some bad
connection. Rich Baker will work on this problem when he arrives
next month.
The DATA command on SCINTSOFT lists the most recent (yesterday and
today) MACRO data runs and free disk space. The shift worker is
supposed to check the free disk space upon arrival and departure
everyday. The original DATA command first gave you several lines of
error messages of no files found, then a list of data runs and free
disk space. Doug wasn't satisfied with this set-up that it did not
provide information as to what the minimum free disk space should be
and what action to take if the free disk space got too small. He
wasn't happy either about the error messages. So Erik made some
corrections and now the DATA command doesn't have error messages in
the beginning any more.
Doug is working on the new shift scheme, like the number of
American plus PISA shifts would be cut in half in the near future and
a new technician will be hired by the PISA group. People will get his
detailed report soon.
The new shift worker, Chuck Bower, arrived last weekend with 5
new attico SMT triggers from Caltech. The triggers use +12v power
supply and they draw a lot of current. To utilize our available camac
crates, (unless some of you would like to donate $70,000 for new and
powerful camac crates), the current settings would be changed in such
a way that most of the +24v current is diverted to +12v supply. We
hope it would not generate too much problem in the camac power supply,
we don't even have any spare KS 1502 camac crate here. If the camac
crate can't handle the power and blows up, people will be strongly
encouraged to make friends with millionaires and billionaires around
in the world. Maybe it's a good idea for us to fly the first class
from now on.
Erik commented that there's no WFD readout from attico layers.
Late last week we had system error in uVAX1, message number 5C4C,
showing up on the acquisiton console screen every few seconds. And on
the uVAX1 computer there's a write error when executing equipment 42.
Doug and Maurizio investigated into this problem, they switched
cables and VIC modules around. About the twentith time they performed
this switch, everything came back to normal again. So it may be
another bad connection.
The Wrong Czar, Maurizio, has been working on the wrong list. It
will be a weekly update of the problems we have had.
Thanks to the parts supplied by the Texas A&M group, HV card is
partially fixed. Paolo resoldered some pins and, voila, it worked. So
the HV system of uVAX1 is back to normal function. But he feared
that it might break again sometime, he suspected that there is a
broken chip in the working card. And Paolo noticed that when HV
control card gets commands from EMILY and some other source, it is
puzzled and doesn't know what to do. He suggested that one user at a
time should be allowed to talk to HV controller. Erik is working on
implementing a fix for this problem.
In the last shift report we discussed the possibility of obtaining
a new HV mainframe, due to the supposed incompatibility of our spare.
Bob Webb has pointed out that there's not any real incompatibility.
Even if the label on the spare 1442 states 30v instead of 31.5v, the
two units supply exactly the same voltage.
Nina is in the process of cleaning up the LED calibration program,
[scintsoft.led.dev]led_calib.for, and changing all the hardwired wait
time to parameters that can be changed in an external command file.
The goal is to push the calibration as fast as we could without
breaking the system apart. She added more comments to the command
files in [scintsoft.led.dev] so other people can use them later on.
Nina read through materials in the counting house to update the magic
book for shifters. Chuck would continue this work after she leaves.
He and Paolo will work on producing reference histograms for the
VXMACA histogram presenter.
Last maintenance day Maurizio and Erik investigated the
problem of low laser light output from uVAX3. They found that the SM6
laser has to have its plasma cartridge replaced. They suspected the
SM4 laser has the same problem.
The computer connection with the external lab got worse these past
few days, the only fix used to be to unplug the DEC bridge for ten
seconds. Today this DEC brige has been replaced by DEC engineer.
Note: There has been a couple mistakes in the last shift report.
- The parts we needed to fix HV controller card were actually
supplied by Texas A&M and not by LeCroy as stated (we tried to order
them from LeCroy in Rome, but they don't have the parts we wanted).
- About the "big inductor" to be installed between the two ground
systems in the labs to try to reduce spikes on the main power line,
Paolo pointed it out that it was an idea of the electric engineering
staff at the labs, and not his own.